My personal favorite is Professor Anders. Love the Hawk, it can pretty much take down anything with ease, except bases......they couldn't take out a base for anything. But other than that it destroys, Swarm of fully upgraded locusts can turn into a pile of scrap in about 20 seconds.
Just back them up with Scorpions (Or grizzlies in 2v2 or 3v3) Or wasrthogs, or pretty much anything effective and building destroying, and you're all set.