I love Cirque du Soleil and have seen almost every show, both their traveling tent and permanent stage shows in Las Vegas. Tickets can be pricey for some of their shows like "O", which run from $99-$150 a seat, but to celebrate 25 Years of Cirque du Soleil, you can buy one ticket regularly priced ticket and bring a friend for $25; call 866-998-4833 to get this deal offered ONLY by calling them. The discount is for a limited amount of tickets at ALL shows, so call soon if you want a ticket to the most entertaining shows I know of at the most unheard of prices I've ever seen!
If you want to stay at the Bellagio while you see "O", they have a great deal from May 26-October 1, 2009; if you stay 2 nights, they will give you the third one free. The rooms start at $159 so if you do the math that works out to $106 per room per night! Just use code BSUMGB to get this offer; the code also offers a 25% discount off tickets to "O"; but the deal I wrote about above is MUCH better if you can get the dates you want, after all for about what you would pay for a movie with popcorn and a soda, you'll get one of the best live performances in Las Vegas!