I can tell you I use Avast and have for about 3 yrs now, I have had 0 problems with my PC and gaming. I do get alerts every so often, if you are securing more than one PC they have multi PC deals.
Gargoyle will tell you he uses Trend Micro
Let me know if you have any questions I can answer about avast. They do have a free antivirus only that you can try out.