Buffets are to spendy. I'm a grazer, eat 6 times a day but small meals, so buffets are a waste on me.
I hit....
Gambler's Special At Mr. Lucky's 24/7 in the Hard Rock Hotel. Steak, three grilled shrimp, a choice of potato or broccoli and a salad. It's not on the menu -- you'll have to ask your server -- and is available around the clock. They ask for a players club card but usually don't hassle you much if you don't have it. I heard they now require you to buy a beverage too..... $7.77
LaSalsa Cantina for breakfast because its $3.95. Not the best food but cheap.
And Secrete Pizza in the Cosmopolitan. Up escalators to third floor, all the way down the hall.
It's not so secrete these days but great pizza by the slice. It's also where a lot of "friendly ladies" conduct business so don't think your a stud when all the ladies are hitting on you.
Then there is Coronado Cafe at a South Point. Its alllll the way down Dean Martin Dr. so you need a car.
Mid-night to 6am, $2.95 breakfast. Like Denny's grand slam style.
Most of the time I just buy the cheap food at the cafés after midnight and throw it in the mini-fridge for the next day. At the Imperial (I think, my memory was a bit.....let's say "cloudy") we got a whole pepperoni pizza for $4.95 and huge sandwich's with chips were $2.95. Fried chicken, 2-piece, with a waffle was $1.99.
I also just have limo (cheaper than cab) swing by Von's and load up on food for the room.
And I've found that if you want cheap eats, look for the sports book. They tend to put a cafe next to it with cheap food. Guess they don't want the gamblers wondering off in search of food.....