I have Vista, it came with my computer... Now, I am not a com p tech person and I have had it roughly for a month. It runs smooth, but there are some minor issues with playing Old games, like you get that weird distortion of colors especially for Fallout 1 and 2... It does have some bug issues, though I have yet to have a serious crash.
It remains to be seen. In the future, I'd opt for an XP based OS. Oh, well, live and learn.