I had 31 costume changes in Tommy, playing 26 characters.
Plus, I did a rather camp, somewhat hilarious production of Sweeney Todd as Tobias, and there was a running gag that I had a costume change for EVERY scene, to the point that if I left the stage for a moment and NO time passed, I would still come on in a different costume.
I worked backstage on a production of The Producers, and I can honestly say that it's the most costume-intensive show I've been a part of.
The picture really doesn't do it justice, as there was were at least three or so gondolas full of costumes.
"I am and always will be the optimist. The hoper of far-flung hopes and dreamer of improbable dreams." - Doctor Who
"Yes, the brutalities of progress are called revolutions. When they are over, men recognize that the human race has been harshly treated but it has moved forward." - Les Miserables
Most would certainly be Les Mis. I had about five or six costumes, but I was changing them all them.
And though I didn't have a lot of costumes, How to Succeed was the most frustrating experience I've ever had with a costume. My window-washer jumpsuit was a velcro tear-away, and it was not only a pain in the ass to put on, but I was constantly worried it wouldn't come off during the performance. Fortunately, I actually loved my costumes in that show.
I am a firm believer in serendipity- all the random pieces coming together in one wonderful moment, when suddenly you see what their purpose was all along.
With Les Mis, the ensemble goes non-stop for the first hour of the show doing a scene then changing their costume.
"If this is going to be a Christian nation that doesn't help the poor, either we have to pretend that Jesus was just as selfish as we are, or we've got to acknowledge that He commanded us to love the poor and serve the needy without condition and then admit that we just don't want to do it." -Stephen Colbert
Two years ago I did a production of "Jerry's Girls" and had 11 separate costumes/changes and every single one was a quick change. There were about 15 in our cast so it was pretty much complete chaos backstage every night. However, we had the best dressers in the world and every actor made their entrances each night. It was utterly exhausting but now it makes any change backstage look like a cakewalk!
"Good Time Charley" - out of town - Boston. 21 costume changes for ensemble including tights. Exhausted by final curtain, a lot from costume changes. Many costumes (and set pieces) trashed by opening at The Palace. Quite a while back.
I would have to second (or third) whoever said Singin' in the Rain. Don, Cosmo, and Lina all have CRAZY changes. The film was never intended to be a stage show, and as a consequence, they are almost never off stage! When I played Lina it wasn't just the costume changes that got me (I think I had about 9 full costumes (with accessories!) but the wig changes did me in. There was regular Lina hair, there was a back up blonde wig for the pie in the face scene (which would frequently end up full of shaving cream!) and then the giant "Marie Antoinette" wig that I went completely into and out of twice a show...9 shows a week! Those costumes were gorgeous though!
I think "The Complete Works of Shakespeare: Abridged" would have to take the cake. :)
Madame Morrible: "So you take the chicken, now it must be a white chicken. The corpse can be any color. And that is the spell for lost luggage!" - The Yellow Brick Road Not Taken
Two of the last 4 shows I did had a record of 12 costume changes: Curtains and Chess. Especially in chess, for such little stage time i was a maniac changing constantly. The only shows I can really remember only having one costume in are Into the Woods and The Mikado.
<------ Me and my friends with patti Lupone at my friends afterparty for her concert with audra mcdonald during the summer of 2007.
"I am sorry but it is an unjust world and virtue is only triumphant in theatricle performances" The Mikado