I really don't have much first-hand experience with Vista, so I supposed I'm a bit biased (I've touched it a few times on my girlfriend's laptop.)

My guy feeling is that you'll find more support for your general use on XP Joy, but maybe that's me. Microsoft should have Windows 7 ready at some point in time and you might be able to just skip from XP to 7. But like I said, I really have no knowledge of Vista, so it'd be interesting to see what sort of features current users like. (flashy-ness aside.)