None of the free AV's score well.
MBAM is for malware and the paid version with real time protection is excellent.
I know everyone will groan at this, but Symantec Corporate scores the best of all the major brands, we run this with the paid version of MBAM, they do play nice together.
Eset which I rarely see compared, is also an excellent product that I would recommend for home users or older PC's.
Your best defense is keeping your equipment up to date and ditching JAVA, Flash and Acrobat.