I always make sure that I make a visit to Numb every time I'm in Caesar's. I'll usually go to Qua (the spa, which is also worth the trip), followed by Numb, and then some gambling. I've never had a bad experience here and you get what you would expect-- overpriced, frozen, alcoholic slushies. But come on! It's Vegas-- what isn't overpriced and alcoholic?
I like to get the small size (16 oz for $10) with a mix of the Purple Haze (Açaí base I think) and the Strawberry Butterfly (sounds so girly..and, uh, it is). But these mixed drinks are quite refreshing. Very sweet, but the alcohol gives it the push it needs. It's mixed with a flavored Skyy vodka and has a Cruzan rum topper. I will get the extra shot (+$3) which is worth it.
TIP: If you really love the place, save your glass. You can bring it in the next time you're there and get $3 off (might be $2...but still, that's tip money in Vegas!)
The service is always great here and the waitresses are also as beautiful as they come at Caesar's. Four stars for consistency!