That is one of the things on my must see list when I do finally get to go to Vegas. I have watched videos of the Bellagio Fountains before and it just looks amazing.
I have watched videos of the fountains performing to winter classics as well as several other songs and each time they have been beautiful to see.
Though I would imagine that it would be much better to see it live and in person. Which is why it is at the very top of my must do list.
Another thing I want to see and experience is the Madame Tussauds Wax Museum. That would also be something that I would just have to see.
Madame Tussauds
Of course there are other things that I want to see and do in Las Vegas as well, however those two things ( the fountains and Museum) are the two things at the top of my list.