This is a hard place to land good deals, although it never hurts to check the hotel's Web site for specials: rates average $250 to $300 much of the year, but during slower weeks you can usually snag a room for around $170 to $180 (competitive in comparison with other high-end Strip properties).
Other hotels (Wynn, Cosmopolitan) have taken over as my preferred place to stay in Vegas, but Mandalay Bay is still a good choice (The Hotel is great too). Stripsteak is a great food option here, even if not staying at the hotel.
agreed with peter. don't take this zoo for granted. it craps on our LA zoo, no joke. don't sleep on this if you haven't been. pay for the sky ride/bus tour, it's worth it -- see animals while you hop from one side of the park to the next.
Not sure when you are traveling, but the Dodgers are in town for a 4 game series starting on the 5th. Again, this is in walking distance from the Hilton. You can't get much more romantic than a baseball game on a cool spring evening.