This hotel is extremely beautiful at night. It is right in the middle of the strip and the amazing water fountain in front of the building makes it impossible not to pay attention to it.
The lobby is beautiful as well and definitely 5-star worthy. This is the classiest hotel I've seen in Vegas. The workers are very polite and friendly.
The best thing about Bellagio in my opinion (besides their water fountain) is their resident show, Cirque de Soleil's "O". Tickets are pretty pricey but definitely worth checking it out. There is nothing like it!