Depends what you like mate. If your happy with using the phone as it comes out of the box, iPhones are great
If you are like me and rather flash the phone and use custom Roms and Kernels, then get a Android phone.
I have a Samsung Galaxy S and using a Custom Rom called F1 and it is super fast, plus if you get bored or that, there are tons of different roms and kernels to use.