I've used many of the top ones on various computers - each has their own special features that I like. McAfee is OK, Norton is good but a memory hog, TrendMicro I disable on ANY computer I sit down on, AVG I've used for years, and my personal favorite is Spyware Doctor. While not necessarily an AntiVirus product, it detects many trojan's and is a required product on any of my comptuers (even on employee computers).