I agree with the beforementioned frogboy's recommendations..
Now.. since MBAB focuses more on PUPs and adware, I'd suggest adding one more on-demand scanner, like HitmanPro, EEK or ESET Online Scanner.
Also, you should add the following extensions to Firefox: WOT & HTTPS Everywhere.
Finally, if you're not using it already, you should install CCleaner to clean your browsing history and improve your PC's performance.