I love Avira Free (the new cloud option in free version is amazing, it helps a little) but Qihoo IS, TS has a good protection, the QVM 2 Engine is amazing, VS 0-Day and infected PC it is more effective Qihoo, the Proactive Defense will ask you (a lot) but for me it is not an issue.
Qihoo IS, TS it reminds me of ThreatFire (Proactive Defense from Qihoo)
EDIT: Thank you people for the friendly welcome