I have had two laptops in the past 5 years, one of them I got from a goodwill for $10, and it ended up being word processing only (it only had windows 95 on it, and 16MB of ram, and something like a 513MB HD), and I ended up taking it apart, and losing most of the pieces.
Then for Christmas I got a decent laptop, but the battery was fried, so I didn't really have going ANYWHERE as an option, but I still sported it for the month before it got stolen (I'm still racking my brains to figure out why I didn't use my desktop PC at the time... I think I didn't have an XP disk to fix it...)
All in all, I would MUCH rather have a laptop, simply because I'm not really a gamer, and unless it's good old ePSX, or zsnes, or gen+, it's not being used on my computer that often.
I'm a pretty big music person too, so if I have a portable HD with all my music, movies, and roms (legal mind you), so I can use a laptop on the go, and my PC at home, I'm good.
Sometimes I long to sit at a desk, and sometimes I long to just lay in bed and surf the net, and sometimes I just wanna go to a friend's house and do things, with my own personal settings, and not have to bring my PC with (I do if I need to, mind you)
All in all, I would vote laptop.