I personally have been using
Bullguard for about the last seven years and I think it's great. It's designed to be compatible with all manner of games and online gaming especially, and has all other neat features such as link-scanner (preventing you from accessing a weblink loaded with viruses), real time-scanning and other nice goodies.
The only problem I've had with it has been during a quick-scan or full computer scan (which i schedule daily/weekly respectively) which can be a bit CPU intensive especially when running other CPU intensive programs. But if you schedule them for times when you're not using your computer (eg. while cooking dinner!) then you don't even notice it's there until it warns you of a hacking attempt or virus/malware (but the popups do not appear if you're in another program, eg. a game, but will appear when you tab out or close it).
And even better, its on special at the moment if you like what you see from a free trial (up to 30 days, but the sale ends in 10 days!)