I love the Mandalay Bay atmosphere. I think this is a common theme in hotels at the end of the strip (think Wynn) that has EVERYTHING so you don't have to leave and the fact that it's far doesn't phase you so much.
First, restaurant wise, Mandalay bay is packed with so much good food. They have three Michelin star recipient restaurants and although some of them were over-hyped, most are quite delicious. The variety is astonishing for one little hotel / casino. The casino area is also very large and has everything from $10 tables and $0.01 slots to $100 tables. If anything, you can always take the tram to the nearby Luxor and Excalibur to find even cheaper tables since its so convenient to do so.
The interior is nice, and the atmosphere is pleasant. They have an awesome pool area / Mandalay Beach and THEhotel is posh and overflowing with understated elegance. There are also a variety of shops to keep your shopping juices going and a Fat Tuesday to keep the alcohol flowing. There is so much to do you won't want to leave!