@Malik: These feel...totally different than your normal style. 2, 3 and 5 are very interesting. They have the same composition. I don't want to sound rude or anything and it isn't bad but did you use a tut for these? If not well done I have not seen sigs with bits of the middle part on the outer edges in awhile!
I'd be careful with sprite sigs, they usually requite a lot more effects to be pulled off well and as you have them I'd even sharpen the sprite more than they are.
The first sig you posted is the best out of all 5, imo.
@Roach: I'd say the same thing Inyro said and I'd also look up some tuts. They give many helpful tips! You can find them here >
http://www.deviantart.com
There you can just type in the search bar "Photoshop (or Gimp) Tutorials" and you'll get a lot of results!
@ Inyro : Ok for the first sig, it's, very busy. Try to focus some of the effects to just stick around the focal to make it REALLY pop out at us. Basically the left side has too much going on, but I do want to say the render is blended very well with the sig.
EDIT: Also on the first sig, I'm not sure if that's a Liquify effect you used but I'd tone it down maybe a little, it gives the sig too many directions. That's opinional though.
For the 2nd sig I see you've done something a lot of people do with sigs. "The Floating Head". Try to bring him out more than just the head, show some of his shoulders. Also work on some depth in that one, it's very flat. The text is good! Text is hard to do.
EDIT: I haven't made a "good" sig in a long time, but hopefully this is decent, what do you think?
I seem to have a love hate relationship with it.