it is a user face friendly, Ubunto is one of the nicest Linux put together with a nice GUI
down load the demo CD to get a feel of it see if you like it or not. any reason why you hate Vista ? driver ? compatible issued ? or too slow ? I was a beta tester for Vista and used it after it was release for about 1 months, I didn't like it because it was driver issued, slowness so I switch it back to the XP. I would used Ubunto too, but because I play game and Ubunto can't run all the application I had like VPN to Nortel switch so I stick with the good old XP.
I just got me a nice desktop rig, I load in a Vista 64 and been using it, it is a resource hog but the hardware I had is far more advance then Vista 64 can eat up, it turn out awesome to use Vista now.
it is all depend what you want to do. are you gaming ? if you are stick with XP, but if you must use Vista , then make sure you are update with all the patch and search for some stand alone patch that not include in the update, look at this article to get the stand alond update http://www.extremetech.com/article2/...2177716,00.asp
if you like to try out linux and have no interest in play game, then it will be a good choice also, but be warn, it won't run all application from the windows unless you want to install something like Crossover to emulate the windows binary.