Vista is actually a good OS, despite what everybody says. Most people who say it suck were probably trying to run it on Celeron CPUs with 512 MB of RAM and an Intel GMA. It actually ran perfectly fine, even on my laptop from 2003 with a Pentium M 1.6 GHz, 2 GB of DDR RAM, and an ATi Mobility Radeon 7500 (although I had to remove it and replace it with Windows XP, cuz I'm gonna need to put Vista on my desktop PC again in a few days, as my Windows 7 Beta expires).
Basically, make sure that you have a decent processor (anything better than an Intel Celeron/AMD Sempron) and 2 GB of RAM at the least.