i have used quickheal, norton. mcafee, f-prot, avast, avg, panda & nod32.
i prefer to use BITDEFENDER. i think its the best ! its got a high detection rate, easy on the resources, good features and options ( can disable it on a fly, if you find it dragging your pc), good international rating, a 100% VB pass. check out *www.toptenreviews.com 8)