Both are excellent, and their Pros/Cons compliment one another.
HitmanPro has the advantage of being a cloud-based scanner with access to multiple AV vendors.
Disadvantage; Free download use it limited to scanning only, 30-day trial for malware removal.
Malwarebytes has the advantage of being a great scanner to find and remove malware for free.
Disadvantage; Not portable, not cloud-based with access to multiple AV vendors.
Comparison ignores MBAM Pro.
If I were to choose one or the other, I would be stuck on the decision, but for most users I'd recommend Malwarebytes Anti-Malware. (You can't beat free removal).