I just got back from Vegas a little while ago, been to several of the shows there (not at once). My favorites of the ones I've seen have been KA, Mystere, Phantom of the Opera, Blue Man. I have been disappointed by Zumanity (horrible cabare things), Mama Mia, O (not horrible only okay), Danny Gains is okay, and the Comedy Clubs are kind of hit or miss sometimes. Also the Ferrari Dealership at the Wynn isn't really worth the $10 considering you can't get closer than 5ft to ANY car, can't take pictures, and constantly have some guy breathing down your next to make sure you don't "touch the velvet rope."
I enjoy Vegas a lot, I enjoy all the food, the atmosphere, the good shows, and gambling a little. "Love" will be on the next trip around, just my opinion about the shows at Vegas.
Tyson