I've been to Vegas a few times and I'd have to say the Bellagio fountains are still some of my favorite sights I see each time I visit. They are magical and so powerful. My last trip it hit 115 degrees and the mist after the finale was delightful and I liked to just hang out in the aftermath. They are best at night and they are fun to watch from the different view points - from a room, around the side and straight out front.
For $200,000 you can choose the song... ohhh to have that kind of money to blow on something like that!