Sometimes Rogan is downright irritating with some of his commentary, that last UFC he did was pretty damn good though. My favorite commentary of all-time was when they had Tank Abbott sitting on the side talking shit...I can't remember which UFC this was, but I think it was around 11 or so, they had some dude fighting that was missing his right pectoral muscle and when the guy starts losing, Tank throws out,"I'll be he wishes he had that right pectorial right about now." Later on he's like,"I don't understand all this hugging and shaking hands after the fight, I came here to fight, not play grab ass with my opponent."
I don't know why they can't find color commentary from guys who actually understand the sport, Bas does a decent job in Pride, but it still isn't as good as boxing's commentators who tend to display an intimate understanding of the sport.
Phil Baroni did a ROTR awhile back that was good.