Dovii has been my favorite I have kept so far.
If you stood at one end of the tank and he was on the other, he would flare his gills, cock his head sideways, and swim in an angry circle while evily eyeballing you.
Not to mention the ravenous attacks on my algae scrubber, siphon, and generally anything you put in the tank that he didn't like.
Too bad I had to get rid of my 240 gallon. I'd have loved to keep him.
My favorite list that doesn't get gigantic:
Haitiensis
Grammodes
Lyonsi
Trimac
Myersi
Argentea