I've watched nearly all of the shows on the strip as well as a few traveling Cirque's. Not to discount the other shows (as I am big fan of Cirque's), but Absinthe was my favorite. It's a good mix of comedy, acrobatic acts, etc. Note, the humor is raunchy and you'll be in the line of fire for harassment if you sit in the first two rows. However, it's hilarious if you can take a joke.
The show is under a big top tent and located in front of Caesar's. The setting adds a sense of vaudeville-esque authenticity to it. The first two rows are VIP seating and have seat cushions. The reason I mention this is because the chairs are regular wooden chairs. I hear that the chairs without cushions can get uncomfortable throughout the show. As a tip (if you aren't a local), you can buy discounted tickets from Vegas.com.