Quite simply, one of the best places to drink a bottle of wine in Vegas. The staff is a bit snobby, but in my opinion, every wine drinker should be a little snobby considering some of the prices for a good bottle of wine.
The tricky thing is knowing when this place is open, considering the drive from the Strip (unless you happen to be staying at the Rio).
Other than that, it's got a great atmosphere and a great bottle selection.