Another good one is Superantispyware. This one picks up some of the other odds and sods that Malwarebytes misses, mainly the milder nasties such as tracking cookies.

http://www.superantispyware.com/

Just click on the red free edition, download and install it. Remember to update it before running a scan. It also sits quietly monitoring in the background which Malwarebytes doesn't unless you pay for their full version.