Martin Lawrence is number one on my crap parade. I don't think I've chuckled at his stand-up, movies, or TV shows once. 100% pure crap.
And Dennis Miller used to be funny, back when his thesaurus induced banter seemed like it just rolled of his tongue. In recent years though, it almost seems like he's forcing it. You can almost see him skimming through a dictionary and thesaurus before every appearance, sweating while trying to figure out how to turn the sentence "I want a sandwich" into "I covet the cheesy nourishment of a grilled curd on rye that could only be fathomed of in the Cheddar Gorge caves themselves."