Both NY-NY and Paris are neat, but I think I liked Paris a little more because the rooms were cuter. (I just remember them being nicely decorated) though I think the shops inside were kind of boring. But, it's right across from the Bellagio, so you don't have to walk far to see the water show and it's a nice view.
I haven't had a room in the MGM, but I think my mom has and she had good things to say about it. It's pretty cool on the inside (love those aquariums.)

