Cirque du Soleil has mounted no less than eight ongoing shows in Las Vegas at once, each at a different casino, as of 2010. How? While Mystere, the first, is basically a touring show taking advantage of a fixed abode, most of the other shows put a twist on their style:
"O" uses a giant pool for its stage, so all the acts incorporate water in some way (i.e. diving and synchronized swimming).
Zumanity is adults-only.
KA has a linear plotline told through its acts, plus two moving stages to create its settings.
LOVE is themed around the music of The Beatles; there's more dance than usual, too.
Criss Angel BeLIEve was initially a magic show/circus hybrid where the troupe played a supporting role to Criss Angel, but after a Retool it's a conventional magic show with some Cirque filigree.
Animal Crackers, in a sequence absent from the movie version, has a scene in the second act that changes the time and place to Ancien Régime France, with Spaulding as Louis XV, Mrs. Rittenhouse as the Queen, Mrs. Whitehead as Du Barry, and John as the great painter Monsieur Jean Jacques Beaugard.
Tachyon Drift - the episode where the ship forces everyone to speak in Norwegian, to make Doctor Jensen feel more included.
The Yeomen of the Guard is very different from Gilbert and Sullivan's other collaborations, to accommodate Sullivan's desire to do more serious work. Yeomen is much darker in tone than other G&S works; it's an outright tragedy instead of the usual light comedy, with a downer ending instead of the usual armload of marriages; it alone has no satire of British institutions; it alone has a cast that includes someone who actually existed; it alone starts with a solo instead of the usual chorus; and it alone has an opera-style overture instead of the usual medley of tunes from the show.
Ani is a departure from the rest of Team Starkid's work in that it's not a musical, per se; it doesn't have nearly as many songs as their other shows, and the songs are performed in the background instead of by the characters.