It was my first time at the Bellagio and after staying at the Hard Rock, and Cosmopolitan I've realized that the Bellagio is the way to go. I'm in my mid 30's now and seeing all the teeny boppers run around at the Cosmopolitain drives me crazy and made me appreciate my stay at B more. I prefer the classic luxury Bellagio exudes to the trendy it resort of C.
The rooms are nice and the one we got with the view of the fountains was gorgeous. This is definitely where we're staying next time we come in about 6 months!