System Image backup
Malwarebytes
SuperAntiSpyware
WinPatrol
A 2-way Firewall (Online Armor, PrivateFirewall, Comodo, Outpost, native Windows FW w/Advanced Security unless you have XP or older)
Firefox w/ various security add-ons (NoScript, AdblockPlus, RequestPolicy, BettterPrivacy, etc.
Sandbox your browser, either with Avast! Pro's sandbox or something like Sandboxie.
All that together might = overkill, definitely don't try all at once, but good options there. Definitely better than running two residents AV's like you were doing.