Vista 64 & AntiVirus

Can anyone suggest a good Anti-Virus/Anti-Spyware for a Vista 64-bit? I saw the poll thread but its old, things have changed since 06 when it first started. Weather its free or paying for it I'd like to get a nice one since im sure im starting to get some Virus's on my rig and thats what has been causing issues with mysetup and would like to fix it now and before I do a reformat and reinstall as well.

Kaspersky 2009 looks good and I know I've only heard good things about it through out the years. Downside the package I'd be intrested in is $80. If anyone has a sight or spot that I could nab it for $50-60 I'd be totally game for that.

Is there any other ones out there that are... solid as this one that I should be considering, weather its free or paying.

avast

I'm using XP 64bit and AVG, loving it so far, had Norton Corporate Edition 9 (my Dad gets free service from his gov office) and AVG is much smaller, uses less mem to run and seems to catch more as well. Also using COMODO firewall, like it too. For spy/ad ware I just Spybot S&D every once in awhile.