iPhone 3G/S cases?

I'll keep this simple:
Basically, I'm a clumsy twit.
And as we've all found out the hard way, clumsy people + iPhone = smashy smashy.
And I guess a fair few of you have iPhone's (I hope), just wondering if anyone could recommend a case to me?
It needs to be:

• stylish (like, with some cool patterns on the back)
• practical (protect it in case i drop it)
• slim (i.e. because the 3GS is bulky enough as it is, I don't want it to be any bigger)

I already bought a couple of "invisibleSHIELD" things for the front, so it doesn't need to protect the front. Just the back.
The price doesn't matter; I would rather invest in something of high quality than save on something which won't protect it.
Any helpful suggestions will be +repped, and I'll even give you a cookie.