Excellent topic !
Real time:
Avira internet security 2012
Emsisoft antimalware
Superantispyware pro
Spy protector (security task manager)
and they all play very well together
Internet:
Chrome 17 with WOT. AdMuncher
On demand:
Malwarebytes anti malware
software testing:
Timefreeze 2, if you run into any problems just reboot and all is well again.
and to top it all off..Revo uninstaller pro to keep things nice and clean. I do use Glarys pro and ccleaner but they are mostly stand by's.
I Haven't spent a dime in repairs in 2 years. only money spent was for upgrade of HDD