So, full disclosure: I hate the Strip. I'm not your average Las Vegas tourist, because, well, my extended family is from here, so ya know, I'm over it.
That said, there are certain things within the Strip's confines that I love, and the Bellagio's Conservatory is definitely in the top ten of things I love that are also free (so rare in Vegas!). I always take my Vegas virigins here when I accompany them on a Strip sojourn.
The designers that they bring in every season are always so inspired. One summer there were leaping water fountain arches you could walk under. Also, the winter display always tends to be spectacular with christmas garb.
Most of all, I love that this display completely changes, which is very much in the spirit of Vegas, a city that never seems to stop radically changing all the time. Also, since Vegas is not much for high art or charity, this is one of those exceptions where the auspices of the wealthy hotelier trickle down to the plebeians for greater public enjoyment.