As someone who's been to Vegas several times, I'd offer up the Bellagio, the Mirage, or also the Wynn as well as places to stay. However, my most recent trip a month ago, we stayed at The Cosmopolitan. That has now become my new favorite hotel.
From the moving wall paintings/visual displays, to the Marquee Beach Club Day Parties w/ my favorite DJ playing there, to a 3 story bar encased in a chandelier, its freaking awesome. The view of the strip is amazing too if you end up on a high enough floor. We were on the 69th floor (not even kidding)....