The Moulin Rouge is one of the most famous cabarets in the world and no trip to Paris is complete if you don't go. I've been there many, many times and I never get tired of it. However, there are some cautions when you buy tickets.
First, if you buy a ticket for one of the tours that package a visit to the Eiffel Tower, a Seine cruise and a visit to the Moulin Rouge all in one, or are part of some other tour, be prepared to have the worst seats in the place. The large tours are all shoved together in seats in the rear...many with little view of the stage and almost impossible to get out of if you have to go to the bathroom, etc. Also, the tour customers usually get the worst service, mostly because the waiters can't even negotiate a way to many of the tables and their tips are minimal for the tour customers. My advice... purchase your tickets at the Moulin Rouge, not as a tour or online.
Now, you will have a wonderful experience if you make a little more effort. First, go by the Moulin Rouge to make a reservation at the desk, either the day of the show or a day or two in advance if you want (the day of the show is best...but I always visit or call a number of days in advance to make sure of the ticket situation). You really can't reserve a specific seat, but you can leave your name and make a reservation...making sure the gal notes that you do not want to sit in the upper tiers or on the side. You will pay at the end of the performance when the waiter presents you with the bill. Also, make sure (subtly) when you arrive that you know how they allocate seats and remind them once again that you want a good seat. Remember the old adage, the squeaky wheel gets the grease (but do all of this with the greatest of care...if you are abrasive in any way, you'll get a crappy seat - guaranteed).
The night of the show (the 11pm performance is best...the food at the earlier performances is not all that good anyway) you go to the desk, tell them you have a reservation and then wait to be seated. I have never tipped the fellow before being seated, but always secretly hand him 20 or 30 Euros when I'm seated (if the seats are good). Do not make a production of tipping for your seat... they don't like that!
Now, why go to the Moulin Rouge?
OK, I've seen every show in Vegas, I've been to the Lido and the Follies Bergere and the Moulin Rouge is a similar type of show... so why go? Because it's history. You walk in the footsteps of the great artists of the "Belle Époque", where the Can-Can became famous, and where some of the greatest stars of the last century have appeared. It is more that a show... it is a place where you can rub shoulders with the ghosts of Toulouse-Lautrec, Collette, Josephine Baker, Edith Piaf and hundreds of others. read more