I nominate MGM's breakfast buffet, but this is perhaps only useful to FT SkyLoft guests. This was late 2005, so maybe someone else can say if it is better or worse since then.

1. I second bocastephen and other posters' ^ for kebabs at the Aladdin.
2. Bellagio because we were there and didn't try Wynn at the time. Due to our dissatisfaction with our (bar wait staff) issues here Bellagio very kindly took this cost off our bill upon checkout. ^

Per the main buffet thread, if possible, learn how to obtain a line pass from the pit boss where you are playing the tables, if your casino has line passes.
No FTer need wait in line!

PS. I was waiting for a reference to a Jimmy Buffet do or a BH shareholder meeting/Do happening in vegas!