The Bacchanal Buffet at Caesars Palace is probably the best quality and variety of food, but also the most expensive. The Wynn is excellent...the Bellagio WAS great...don't know now under new owners, I heard the place has deteriorated. Aria is pretty good. I would rate the Rio as fair; not good (stayed there last year for the
wsop). Red Rock Resort is decent, but far from the strip
Buffets to stay away from...got comped to free buffets at the Mirage...it wasn't worth the walk to get there. Luxor and Excalibur are mediocre to poor as well.
Heard good things about Paris, but never ate there myself.