We stayed at the Bellagio Hotel in Las Vegas last month and it was overall a great hotel.
Pros: right in the middle of the Las Vegas strip. You walk out the front door of the hotel and you are right on the strip. We booked a top floor suite facing the magnificent fountain that shoots off every 30 minutes. We faced the strip and the fountain and man, at night it was amazing with all the lights and fountain going off. The pool here is amazing too so even if you are not a party person, this is a great place to relax.
Cons: If you want to stay in the main Bellagio Tower facing the strip and fountain, in order to get up you your room you have to walk through the casino where there is lots of smoke smell. I understand this is a casino but for I don't smoke or drink so this was a turn off. Had to leave 2 days early due to amount of smoke affecting my wife and kids.
Overall, if you want best hotel experience in Las Vegas, I'd recommend the Bellagio over Cesars Palace!