I think you find around here laptop with Vista is easy most common choice for personal. I advise this as good option. Laptop with Vista will often be no deposit pay over time.
Vista is probably Windows best foray into graphic interface since Windows 3.1/95/98SE winning run, though many disagree until they actually buy and master Vista.
If you have Vista 32bit and clutter your desktop (like download and run from desktop instead of, say, Program Files) and bloat out your Start Menu | Programs | Startup then your computer is gonna crawl.
Usual buy Vista with one year paid antivirus - Norton, Trend Micro, etc... Must do something when sub runs out at years end but many users delay because they still paying off terms and not willing to shell out any more cash. Very common situation round here.