Depends on how much you're willing to pay. One of the best steaks I've ever had was at Shula's, in the WDW Dolphin. You're going to pay a premium for it, though. I'll be eating at the Yachtsman on my birthday in a week or so, and I hear they do a great piece of beef, as well.
As for ribs, I can only say that I've read that the Sci-Fi in Hollywood Studios has good ribs. I haven't had them myself.