My favorite is Caesars Palace. We stayed at the MGM once and had a bad experience where our room was not cleaned. A lot of people love it but that was not our experience. After complaining we were offered a free stay for our next visit but we did not return during the time frame.

If you plan to stay on the strip the whole time then you will not need a rental car. Traffic is heavy enough that it is faster to just walk or ride the monorail. The Donny and Marie show should be great! What a blast from the past! If you plan to go any other shows then I would recommend the George Wallace late night show at the Flamingo. With a Thursday through Monday stay you should have a great time.