Just saw Ray Romano and Kevin James at the Mirage as well as David Spade at PH last weekend. I'll tell however that the funniest guy we saw was Vinnie Favorito at O'sheas. Not recommended for those who want G rated humor or to be left alone in the audience, but if you don't mind being the focus of a few jokes he is very quick witted and sharp. Although I bought my tickets in advance you can probably get 2 for 1 on the day of the show.
Romano and Spade were good but for 100-130 per ticket I would have expected more. Kevin James did a very short opening act for Romano and really didn't put out much effort. The two of them on stage at the end taking audience questions was also a waste of time as it was just one girl after another asking for a hug. Spades opening act Todd Glass was also funny. Coincidentally David Spade had dinner at the next table over from us at Koi restaurant in PH.
While I'm at it, Mac King in the afternoon at Harrahs is a great show. His magic is very good and he is very funny. Bring the kids to this show.