If you like Classic cars, you'll love The Auto Collections at Imperial Palace.
Even if you're not really into cars, it's a cool place to kill some time before a night of hard partying on the strip.
Plus, if you go onto their website you can print out free tickets. Anything free in Vegas is cool. I loved all the old Rolls-Royce Phantoms and the classic 50's cars like the 1957 Baby Blue Chevy Bel Air.
Honestly though, I wouldn't have paid the $8 admission price. It was cool and all but I'm not much of a car guy and I would rather put the $16 (the cost for my wife and I) we would have paid towards some tasty treats. Since it was free, I'm a fan.