Shadow and Silver, LOL. I'm not surprised, seeing how these two seem to cause some kind of reaction in people, be it positive or negative.
Big's concepts are too cool for his dopey personality. Number 4 looks like a stoner, kinda makes sense when you're a big ass cat lazing about and your best friend is a "normal" frog that you have 1-way conversations with.
All of Cream's designs are just adorable. Kangaroo mouse Cream's feet caught me off gaurd, but then I remembered that Sonic Team haven't really nailed down bare feet designs outside of robots.