1A - 6/10 - I like the concept here, and the execution is pretty nice. The colors all match up pretty well, and there is a good amount of blending. I'll point out that it is a bit undersaturated (maybe could do with some more colors in general) and a bit too bright on the top right (so you can't read the text effectively. You should have made it a bit darker so it's still readable while not being so dark as to be confused as the main text.) It seems that her right shoulder is a bit pointy ... not sure if that was a mistake with the eraser tool, but that is a bit obvious. Overall, pretty decent.
1B - 5/10 - Decent attempt, but there's a few flaws here that really detract from the general sig. I'm not familiar with the character so I'm not sure if there's an element of the time travel theme that is being followed here, so I won't comment on that. However, with the clock and the Eiffel tower, their blending is a bit off - they seem to be just pasted in without any regard for blending (some effects on top of them around the edges would help make it appear as if it was in the background). The fire effects are too bright, and a bit too sharp. Some blurring would have been nice, but it seems as though the foreground was sharpened without the background being blurred. Also, I think the choice of font for text could use a little work. Either way, I enjoy the effects. By the way ... what's with that face to the bottom right of the subject?
2A - 3/10 - To be honest, I'm not quite sure what is going on here. There's way too much blue just ... everywhere. I think the goal here is that there is supposed to be a sorceress looking through a portal of some sort at a futuristic time, but that's not what I'm getting here. What it looks like to me is there is a scene of rain that has been whitewashed at the bottom and ripped in the left side to reveal something else underneath (referencing the jagged edges). I think the biggest thing here is the white light - it's just way too overpowering relative to the brightness of all of the other aspects (rather, lack there of). One thing that would have helped a good bit is a thick black border, probably just the horizontal bars. That would introduce some contrast to the white light and make it less overpowering. Additionally, the top right corner is quite bare - I'd suggest putting some sort of moon in there, maybe a few space stocks set on screen to just add some diversity to the background. One thing I must say I like is the text though, good job on that.
2B - 4/10 - While it is a decent sig, I'm not quite sure how much work was done here. My guess would be that there are two distinct backgrounds which meet at the white light (which might explain why there seems to be a bit of a blending problem to the left of the bridge), and then some dinosaur renders and that person (archer/hunter, maybe?). The background does look nice, and the green dinosaur to the left has colors that blend pretty well with the entire scene (though the blueish tint to the left of the dinosaur is a bit off. Mess with curves /levels to try and fix that). The biggest thing for me here is the RED portal on the blue/white background though. It simply doesn't fit - it's a huge eyesore. It is a better attempt at a portal than some of the other pieces, but it could use some work. Also, it seems like it was just "placed there". There's no interaction with the background - I'd suggest you try and make the portal light blue (replace the reddish color on the outside), and greyish-white (replacing the yellow). Then, maybe use a liquify tool on the background to try and distort it slightly to reflect a disruption in space-time. Other than that, decent idea, but a bit too simple for my taste.
3A - 1/10 - This is little more than a text slap. It seems like there's a stock background image off of google (which was placed incorrectly, there's an extra white pixel border on the bottom, though that could be due to the magic wand on the time machine which was then shifted up one pixel), which then has a render placed on it with some lighting that's way too bright and some text that just doesn't fit. Sorry if I'm being a bit harsh ... but there's just really nothing to like here. My assumption is that the artist here is submitting this as one of his or her first pieces ever, which is then acceptable. My advice would be to try and work on blending first and foremost, and then try and tackle the issue of color balance and lighting. Blending in this case could have been achieved by having some elements of the background brought to the foreground (maybe some lightning/ripples in front of the time machine), and a different color background could have worked better (unless a different effect was being attempted, but I would doubt that).
3B - 3/10 - This is roughly on the level of 2A. While it is a little easier to understand what is going on here, and with the theme fitting slightly more directly with the assigned topic, there's quite a few technical flaws that make this a very low scoring piece from me. First of all ... rule of thirds. NEVER (with very few exceptions) place a render in the center ... always have the center /main part of the render 1/3 or so of the width off either edge, depending on the orientation of the render. For the background, I like the colors, though the blur is a bit extreme. Also, you'll notice that there's a bit of a failed effect on the right - I think the overlay stock that was used to color the entire image wasn't wide enough, or was shifted a few pixels to the left by accident. Either way, it's an eyesore. The large white building to the right is way too distracting, though I do want to point out that it fits the lighting scheme, so that's good. It's just that when you blur things, the lighting becomes more prominent (lighter things become even lighter, darker things become even darker), so because it already had a bright light on it that effect just got compounded and it becomes an eyesore. Finally I want to point out the terrible cut on the doctor ... that should have been fixed by blending the hair a little bit. And he's too blurry anyway. Oh, and fix the text while you're at it.
4A - 6/10 - Pretty obvious back to the future sig ... but I'll take it. No points lost for that. My main problem with this is that there is SO much going on - which isn't always a problem - in this case. The effects are pretty decent, and there's a good understanding of blending and lighting and such. I would have liked to have seen the character (Marty, is it?) be a little sharper and have the background have a bit more depth of field, which, in an item like a car, is pretty easy to achieve. Another bit to consider is that the entire left side is just too bright, and that brightness doesn't really follow a flow of the image (ie the general line of the car), it's just ... there. Same thing for the bottom right. While the colors are mostly spot-on, they're generally oversaturated. And I'm not exactly sure what's going on in the top right corner. Oh, and finally I think the sig is a little small for everything going on in it, but that's just personal preference again.
4B - 7/10 - I quite like this, actually. The colors are nice, the concept is great, but there are a few things that throw it off for me. First and foremost is those few lines coming from the white source of light ... it seems that there was a stock image off of a site that you forgot to erase lines from to purchase legally. Also, this does fit to the rule of thirds better than an example earlier, but it's still a bit off. The thing that I really don't like (and that might just be a problem with the way the renders are arranged) is that the guns go basically to the edge of the canvas, which is a problem in my eyes. Also, the blending for the renders, while interesting, needs some work to match the rest of the sig. The biggest thing was probably the text though - I think you can fix that bug by saving, closing PS and restarting. Other than that, I don't have much to say about it. Good piece.
5A - 7/10 - While I like the piece, I think it's overall a bit too dark. It seems like you just took a giant grey layer and set the opacity a bit low, darkening the entire thing while also "greying" it out. So the colors all seem a bit off to me. As for the piece itself, I think the abstractness of the entire image is great, it's well developed and it all fits. The two bright spots are REALLY overwhelming though, especially considering how dark the rest of the image is. Also, I think this might have been better served with less text and a slightly wider canvas.
5B - 6/10 - This one is just WAY too bright for me. While lighting is good, too much lighting can obviously kill an image, as seen here. I like the idea of using the blueprint/sketch of the deLorean in the background, but I don't particularly like the caricatures of the characters. The colors themselves are pretty good, actually, and they reflect nicely onto the characters. However, there's just light EVERYWHERE. There needs to be some contrast, some dark area in this image, of which there is none. Your eyes are constantly redirected to different locations due to the multiple sources of light, so the characters don't get the focus they deserve. Instead of having light at the edges, you might want to consider having light behind the characters, throwing light at them while having the edges blackened/darkened/burned a little bit.
6A - 6/10 - I'm not quite familiar with this character, so as before, I won't be judging based on how well this fits the theme directly. However I will mention that the clocks and such overlayed in the background are a nice touch, they're implemented well. What sets me off about this one is how far the character is angled - if it wasn't fitting in the slot, try not to rotate it to do so next time, and just choose a different character. This might have been better suited to an avatar. Either way, I like the text a lot, this is probably one of the finest examples of text in this selection of signatures. I absolutely love the colors on the bottom right, but since those basically only work because of how far the character is rotated ... I'm feeling slightly neutral about them. You should work on improving the bottom left and top left though, basically the areas in the left apart from the big (perhaps too big) bright light. They're just a bit dull right now in comparison to the rest of the image. Also, on a whole I think the entire thing could do with a bit more black instead of the greenish brown that you've got in dark areas.
6B - 8/10 - I'd say this is one of the better pieces in this round. The first thing that strikes me is that there's a lot of fire ... while it is executed nicely in that it does flow and it does have some blur to add depth, it might have been more interesting if the fire started to thin out toward the top left and we got to see more of the space that's near Dastan's head (to his left). The text is done pretty well, though the "of" is slightly difficult to read - perhaps a stronger drop shadow was needed. The other thing I'm noticing is that the bottom right corner is just slightly too blurry, but that's a minor detail. You'll also notice that inside the border corners there's a bit of a bend in the inner glow, which means that there were better ways to get this effect than the technique used here (and as such to avoid those corner points). But, overall I'd say it's a pretty nice piece. I'd consider using this as a sig .
7A - 5/10 - It's a good signature, perhaps just with an unfortunate pairing. The placement of the various objects is pretty good, and there is some flow established with the moving particles. The render seems to stick out like a bit of a sore thumb, however, even though the colors match up nicely. Some more blending (through smudging, other various effects laid on top of him or otherwise) could really have helped. This is also the first sig that I think really does the clock aspect well, so kudos to you for that. The biggest thing for me here is the text though ... black text on a black background just doesn't do too well, even with a white outer glow. The subtext is nice, but that font and that color on the main text needs to go. One final note, I think this could have done well with a border, because with so much of the clock visible it leaves me wanting more, but that is almost cheated out of me with the sig with a lack of a border - an explicit denial of "more" would be less hurtful, and better for the sig overall.
7B - 8/10 - In this case, the best really is saved for last. I've ranked this as the same as the 6B, simply because I'm not going to give decimal ranks. However, if I were I'd give this a slight edge over 6B, calling this the best in the group. I love the concept and the execution, it's done very well. There are a few things that stick out to me that prevent me from giving it a higher score, however. First and foremost it's that border around the entire sig ... for me, at least, when the large horizontal bars are used there shouldn't be any vertical bars - if there are, they should both be the same thickness. So that's a problem in my book. Also, looking at the bubble c4ds placed around the tardis in the 1886 version (and less visibly so in the 31440 side), I can see that they basically don't match the background. There are better ways of making the tardis stand out, of which I'm sure the artist is aware. I think it might have looked fine without those particular c4ds, perhaps even better. I do really love the split between the two halves though, very nice effects that I can't find any problem with. So good job. As a final note, the text is just crap in both. I understand that text is needed to prevent stealing, but I think in this particular instance the sig would look a LOT better without the text to distract you from the glory of the rest of it.
Sorry if I was a bit harsh guys ... but hey, it's the GGT. It's not meant to be easy . Hopefully people see my comments as helpful more than hurtful, even if people's egos aren't necessarily stroked by these comments. Sorry again .