I honestly don't regret seeing anything on Broadway. Sure, there are things that I don't like but I do regret seeing them. I like being able to say that I saw particular shows just for the sake of being able to say that I saw them.
I would have to say that my only regret in the theatre is walking out of the revival of Company at intermission because I was very sick and it was a stupid move of me to try to leave the house that day. And never getting around to go seeing it before it closes.
I regret being in the mezz for Sweeney Tood the day after I found out I needed glasses and wasn't able to see a thing. Got a major headache just trying to look at the actors and the stage. Never got around to going back before it closed.
However I do not regreat seeing shows like I said before.
"If you try to shag my husband while I am still alive, I will shove the art of motorcycle maintenance up your rancid little Cu**. That's a good dear"
Tom Stoppard's Rock N Roll