I wasn't a fan, either, but mostly because I just don't watch TV so I never saw his Fox show.
I just listened to an interview Terri Gross once did with him on Fresh Air while driving down the highway.. Wow, that guy sounded really smart. He was a real student of comedy from what he said. When he was a kid, he said he studied a lot of comedians but gave special emphasis to Don Rickles, Redd Fox, Richard Pryor, and Steve Allen. Esp. Rickles from what he said. That surprised me because Rickles made so many racial jokes.
He also talked about the Rat Pack (he was in Oceans 11, 12 & 13), and he'd apparently studied them too. Gross asked him one question about the Rat Pack and Bernie Mac went into a long answer about how Frank Sinatra was overrated and how he thought so many other singers were probably a little better, specifically Dean Martin, Mel Torme and Perry Como.
Very interesting conversation and now I wish I'd paid more attention to his work. I guess he stars in a movie called Soul Man that is coming out soon. I'll have to go see it (esp. since Isaac Hayes also is in it and also just died).