Mack and Mabel -- Far and away Herman's best score, but the book is so bad that it doesn't matter
Chess -- I have seen three different productions, original London, original Broadway, and a scaled down version at the Signature Theatre in Shirlington, VA. The last was faraway the most entertaining, but still led me to think that it would never fully work on stage, because it is so cold.
Oklahoma -- Seeing the new version in October. Maybe, I will change my mind. Up to now, I have HATED every version the show I have seen (not a lot).
City of Angels -- Not sure it is a great score, but I have enjoyed it many times. I hate the show (not dislike, hate).
On a Clear Day -- Maybe not a great score, but a very entertaining one. The show definitely falls mega-short.
Rags -- I have not actually seen the show, but have heard that the show covered too much, and suffered because of that. Since it is one of my favorite scores ever (I didn't say best), I have to include this.
Merrily, We Roll Along -- at least in its original production. It was so bad that I didn't even appreciate the score initially. I saw it 2 years ago in Boston and the sort it just about perfect. That production should have been presented by the Roundabout.
Gigi -- I saw two Broadway productions, with the second much better than the first. I think the score is great, really given a terrific OCR, with at least 6-7 great songs. I play it constantly.
Titanic -- Maybe not a great score, but I love a lot of it, particularly the first 15 minutes. IMO the show never came up to the quality of the score, and I was very disappointed, though I did enjoy it.
Song & Dance -- At least on Broadway. Great score, horrible execution on Broadway.