As far as Feast Buffets go, Red Rock has the best one. Love the omelette bar, salad bar, assortment of breads and desserts.
Not the best food you've ever had but it's the best you'll find at the $12 -$20 range. Definitely a wide variety of food and attentive servers who never leave your glass empty.
Champagne Brunch (on the weekends) is the way to go. If you haven't already, sign up for the boarding pass (near Starbucks at the food court) for discounts, it's free.
Newly added: All You Can Drink Beer & Wine for $5.99 (with boarding pass). $6.99 without. Bottoms Up!