Lawry's is easily one of the top places to eat in Las Vegas (or most any city, for that matter).
The prime rib is, of course, the main attraction here. For those who don't want that, though, the corned beef and the turkey are also great.
The atmosphere at Lawry's has a refinement that is lacking from most restaurants. Make sure to wear a collared shirt and slacks (nice jeans at the worst) when you go!