I think monks, after playing one, can be beaten pretty handily as long as you, if playing a hybrid, don't let yourself get Fist of Fury'd below 60%. That means heal early and often.
Brewmasters are pretty easy to deal with, since their damage only comes every 8 seconds.
Warriors on the other hand do retarded damage and if you're talking competitive games with good players they are certainly the best melee right beside ret. I'd say the best 3s comp at the moment is absolutely warrior/ret/resto shaman or druid.