Pepper Mill (Strip) Pretty good food, comfy seats and decent portions.
Circus Circus (Various spots in the Casino) The food is cheap (especially the jumbo hot dogs) and not bad, but I don't suggest trying the dogs too late in the day. Nothing is worse than a quadruple reheated jumbo hot dog with luke warm cheese.
Blue Iguana (Circus Circus) excellent mexican with good portions and fairly comfortable seats.
Aladdin's (Buffet) Spectacular, a ton of stuff to choose from and not just the stuff you find at your run of the mill buffet.