I love Project Dark Fox's drawing if only for the very rough and loose form.
@ Spirit Dragon: I can't really be sure. Did you compose Sonic's form out of basic shapes first? If you wanna be a comic book artist in the future, learning how to construct form that way is one of the most important skills you'll need to know. If you're still not sure what I'm talking about, go online and find a step-by-step tutorial of how to draw Mickey Mouse or something. Look at the various directions.
On second thought, since I'm such a kind and generous soul, here's a video that demonstrates just that. Notice how the artist doesn't trace in Mickey's outline, but rather focuses on his various parts. You'll need to be able to do that.
http://www.metacafe.com/watch/344752/how_to_draw_mickey_mouse/
And then I should also mention that you need to lighten and loosen your touch. Don't expect to erase your preliminary pencil lines if they're so dark. Again, Project Dark Fox provides a most excellent example of what quick sketches should look like. And personally, I find that to be a more enjoyable technique than worrying about getting everything right the first time.
@ Inferno: Upload your pictures via TinyPic, copy and paste the entire "IMG Code for Forums & Message Boards" as a seperate line into your post, and you're good to go.
And nah, feel free to upload original computer-made stuff as well. What we generally don't wanna see are lazy sprite recolors or anything that just smacks of a lack of effort and creativity.