Vista Home Basic came pre-installed with my PC, and it's pretty okay. I like Vista's look and the gadgets, but not much else. Because I have 512MBs of RAM, performance is just terrible as far as loading apps goes, (Sonic Heroes takes nearly 3 minutes to load, and thirty seconds for Firefox. >_>) and it isn't compatible with a lot of the software I use the most. Then there's the crap support for the Vista version of my video drivers...
Vista's performance mostly depends on the PC, although for the most part, I could be running an OS that's ten times as fast and more functional. (Which is why I dual-booted my PC with XP, you have no idea how happy I was just to see Firefox load the instant I clicked on it!)
The performance and compatibility of XP is better on my hardware. So yeah, I have a preference for XP. :P