IMO Billy Incardona is the best.
I always enjoy Buddy Halls work. Jay Helfert is a real pro at commentary and understands how to keep things moving and interesting. Sarah Rousey is someone I always try to get in the booth because she is as funny as she is knowledgeable. Mika has sat in a few times with TAR and I really enjoyed his take on things. Thorsten is one who you dont hear much from but is one of my favorites. Jerry Forsythe is another professional that does all the little things you dont even notice until the next guy doesn't do them.
Commentary is hard to do well and really good commentary can take a good match and make it great.
My dream is to one day get Alex and Earl to commentate on a match between Shane and Bustamante. Just imagine the possibilities.....
Get that match going and Alcano in the mix too if you can. That guy's scary.