I have not had a chance to sample restaurants at Wynn. My recommendations for general tastes would be:
Venetian:
Aquaknox-seafood (oyster bar too)
Bouchon-French
Caesars:
Bradley Ogden
MGM:
Seablue
Nobhill
If you want to include steakhouses Venetian's Delmonicos and MGM's Craftsteak are good choices.