I'm absolutely in love with the Revo2 case. I had the same brand for my past two iPods so I went with it automatically when I got my iPhone. I've dropped my phone a million times and it still looks brand new!
Definitely the best case out there in my opinion, and if it helps, the price is half of what I paid when it first came out. (Though given the choice, I'd still get it again.)
Check on Amazon, or ebay. I got a zebra print case for my ipod touch for $3. I absolutely love it and I get so many compliments on it as well. They had many designs, for both ipod touch and iphone.
Try skinit.com the have several designs to chose from or you can upload your own picture and use it. It doesn't change the look of feel of the phone either. I love mine.
I've been thinking about getting an Iphone and this is the one I think I'm going to get. http://www.iskin.com/solo/features_fit.html Found it when I bought a case for my DD's nano. Also, I've seen some decent reviews for it on youtube.