I've owned an ibook, powerbook, macbook, and unibody mackbookpro.
I always hated how the powerbook had the ports on both sides. Always getting in the way while using a mouse on the right, it looks stupid when a lot of things are connected at my desk, etc. I also hated having the cd drive in the front. The new design of the ports was one of the things that convinced me it was time to go pro again.