kronk is correct. The rio hotel/casino buffet is great. However, might I suggest NOT going during lunch or dinner hours. EVERY 300 lb tub of goo within a 50 mile radius shows up to eat there.
As for nightclubs, RAIN at the palms, "the BEACH" ON paradise ave, and bikiniz nightclub at the rio is pretty good. Here is the second suggestion: GO EARLY if you are going out to a club. get there RIGHT when the line opens up. IF you don't do this, you'll be standing in a line till 2 in the morning or later, IF you get in at all.
wednesdays are hot at club RA at Luxor hotel, mondays (i think) are at studio 54 are good, and there are a ton of other good ones.
some excellent restaurants off the strip are on spring mtn rd, in china town. Some excellent thai, chinese, and japanese restaurants. The nudey bar in china town is sleazy, but the whiskey is cheap, and the women will shove their vagina in your face. Jaguars is right off spring mtn rd on Procyn street. $15 to get in and $10 min for a tiny little drink.