Not too long ago, I attended a dessert and pastry conference in Las Vegas, taking a few extra days to wander around and eat in some local restaurants. I have read that it used to be possible to eat very cheaply here, though much of the food was less than stellar.
Reservations are essential at many of the more-famous restaurants, particularly on weekends.
Where reservations are not accepted, it is often best to go at off-peak hours if you don't enjoy standing in line.