I use Eset Nod version 5 and it has a gaming mode which I use and it runs light in your computer.
http://go.eset.com/us/search-brand?CMP=KNC-g-ag&gclid=CJjx47PamK0CFcNo4AoddQEDmA
You might want to check them out.
LawnDart
Although it is "overkill" on my part, I use ESET's Smart Security Suite 5.0 which also includes Esets NOD 32 5.0
( btw, you can purchase a 3 users ESET SSS 4.0 software from newegg for around $59.00 currently and receive automatic free upgrade to 5.0 version )
it has a very small footprint and has not gave me any issues since I started using ESET many years ago ( I originally used ESET Nod32 antivirus along with zonealarm pro , then switched to ESET Smart secuirty and dumped zonealarm )
but regardless of what a person uses for malware, anti-virus, etc....... it most times is the end user who makes the mistake by clicking on a website or using java/javascript web programs or flash, etc... and actually gives permission and lets the troublemaker in, voluntarily...... letting it bypass your anti-virus or whatever..... then their are those "drive by" websites like facebook, or the like to where you think you are being a cautious websurfer but are not fully versed on how one can become infected...... YMMV
keeping up to date on how to keep from becoming infected by PC virus, malware, spam, rootkits, torjans, etc.... is really more important than just thinking hey, what is the best "anit-virus/ firewall program to use"......
if one was to study the subject and stay on top of it, one can seriously get by not using any type of software firewall or anti-virus software and still be able to surf the web without becoming infected. it just takes good internet using practices and some knowledge of how they are transfered across the net / through email, etc.....
for those that rather rely on software for protection, I would recommend ESET's products..... but regardless of what one uses, none of it is 100% fullproof of protecting you
TC