I would say Avast + MBAM + Sandboxie.

Sandboxie is good.

When ever i download stuff i always put it to sandbox for observation.

IE, FF, Chrome, PDF reader, DVD drive, F drive which is for USB flash drive is automatically run by sandboxie.

Btw! as of now i remove FF and IE in sandboxie because of browser crashing which i created a thread.

http://forum.avast.com/index.php?topic=72404.0