Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
I've found a couple such as http://www.gelaskins.com
but have yet to find a design that really clicks for me. Most of the ones I find tend towards infantile and trendy in a "Keanes eyes" kind of way or Upper Playground kind of thuggy/hipster.
I thought I would be able to find something that complemented the designy look of the MBP without looking so ...trendy?
Any suggestions?

You could always try skinit.com. I think you can even send in your own pictures (though not sure if you have control exactly how they place the picture).

I can say from experience they use 3M skins and they are really tough. I have one on my old Macbook and my new one and neither skin has even been scratched.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.