Vista is fantastic, the new start menu and windows explorer save me loads of time, along with the much improved sleep mode which is handy on my laptop.
I installed on both my desktop(x64) and laptop(x32) last summer and haven't had any issues at all, I always get a chuckle out of the Vista haters desperately scrabbling for imperfections in a pathetic attempt to be one of the 'cool kids'.
For playing games, sure, if you don't want DX10, XP still has the more mature drivers for a negligible performance benefit, but for day to day use Vista is far more polished.
There's also the fact that Vista x64 is far better than XP x64 with regards to stability and driver support.