I have a Hello kitty Case in black and pink from Target (search "hello kitty iphone") It's good for looks and minor scratch protection. I think its super cute.
I have another one or two cheap cases I picked up that aren't anything special.
I just got a Speck Seethru case in Aqua, it looks really neat on my black 3gs. The Seethru is much slimmer than the Candyshell, but it still seems like it would offer okay protection. A Candyshell would be better for really hard, high drops, but for minor or short falls the seethru seems like it would protect. I have the pink/purple Candyshell, its very nice. Speck also has a new black/pink Candyshell and a red Seethru satin that I like and want.
Husband is annoyed by my case obsession. LOL