IMO:
Wynn: Hands down my absolute favorite. I've stayed in different rooms and they're all great. I think they have the best service out of all the hotels in LV ie.white glove doorman. Most comfortable beds. Little flat screen in bathroom.
Cesars: Rooms were nice, new tower is modern looking but not as nice as the Wynn. Service is so so. Best shopping here. I don't gamble here I never win.
Bellagio: Didn't like the room decor. Atmosphere is not exciting for me. Great sightseeing place.
Venetian: Gotta love their 24 hour jacuzzi. All rooms are suites, great for bachelorette parties.
Mandalay bay: Very classy, nice rooms. Crowd a little too old for me. This is my mom's favorite. End of the strip, not convenient to hotel hop. Rum jungle (club/lounge),haven't been there in awhile but it was always a good place to start the night.
MGM: Used to like it but way too smoky for me now. Rooms can use a little renovation.
Treasure Island: If standard room then its very basic. Just to change/shower kind of place. They usually have good deals with their rooms. One of the better suites I've stayed in. One of the suites had 2 separate bathrooms.
I've never stayed in Downtown but I love it, it is so cheesy. I love gambling down there.