My sprites.

[Chris2Balls [:B]]

The first Sonic is good, just needs a bit more contrast, just like the two next ones. The Super Sonic's right eye (our left) is not centred correctly, I suggest you move it more to the left. I'm sure that loads of colours could be got rid of off that computer. I think the Tails edit needs a bit more work on form and shading, and maybe you should make the eyes a bit wider. The Hoodwinx is not very readable (it took me some time to realise he had a tail, not a shell or a hunchback), and I believe he could do with a grey shade (or dark bule or dark brown) to smoothen the black.
That's all I guess.
Keep posting work, I'll check it out!