I often get asked as to which software package provides the best malware protection for Windows. As of right now, that would be Bitdefender in my opinion.
I never was one for the "Security Suites" as they tend to be bloated and ineffective. They do more to get in the way than actual protection. Bitdefender in "Auto Pilot" mode seems to fit the bill. It does slow your system down, but not in a way as to be too annoying. It also has an easy to switch to "Game Mode" which basically shuts itself down while you are gaming.
Just don't forget to turn it back on when you are done.
Also, none of the anti-malware programs protect you 100%. But are you smart enough to wander around without protection? It's like being in the wild-west without a gun, you might get away without one if you are lucky and/or smart, and even if you have one, it won't keep you from getting shot, but it sure can help most of the time.
Go here and buy it and I get a small cut: Bitdefender (and other) software.