About a dozen years ago I saw a scaled down version of The Happy Time at the Signature Theatre in Virginia that was absolute perfection. It demonstrated to me that Gower Champion, despite his Tony wins, was the wrong director for the original production, which was incredibly bloated. Encores should take a look at it if they haven't already done so, because the score is really good and, scaled down, it is a delicate, wonderful experience..
I have a special place in my heart for 70 Girls 70, but I think that Scottsboro Boys would be fourth on my list. It may have been an off performance when I saw it, but Kiss left me cold. I could see the talent that went into it...it just didn't move me the way the movie did. The Visit was also special, but was never going to attract a large audience -- maybe it should have opened off-Broadway.
They did have quite a few clunkers to me, including The Act, Flora, Steel Pier and The Rink. I know there are people on this board who think The Rink is underappreciated; to me, it was the one I enjoyed the least, despite the cast.