most current version of AV support vista.

Free : Avira Antivir, AVG, Avast, Rising (start to love this one)
Paid : Kaspersky, Norton, AVG Pro, Avira, McAfee, BitDefender, CA.

Why dont you visit AV-Comparative.org to see, which virus score the best. At least the result there base on approve methodology..instead of feeling o meter

Personal Preference : I used to use Avira AntiVir Personal Edition (Free). Got same virus engine etc with paid version except, free version do not support POP3 which I do not use at home. Office use is a must (POP3 feature). However, last night, I uninstall Antivir and install Rising Antivirus (free too). This one is more complete, with HIPS, POP, VirtualSpace, and certified by VB100, West Coast Lab and Vista too. Currently doing full system scan...and it found 2 trojan, hidden deeply in my recursive 7zip archive. The best thing I love this rising, it is seriously light, lighter than AVG, Avast, Avira ...to name a few.

Ref : http://www.wilderssecurity.com/showthread.php?t=213187

Paid Version...i will go for Kaspersky AV 2009. RM50 per license...with top notch protection. What else can we ask LoL. Last PC fair, Kaspersky Internet Security 2009, 3 license only RM80 <drooling>.