My all-time favorite is Chess although it opened and closed on Broadway long before I was aware of it, and never returned. However -- as a kind of "Dream trip" Which for some reason I think came up in the Five Questions thread, in 2008 my dude and I got to see one of only two performances of a spectacular production of it at the Royal Albert starring Josh Groban, Edina Menzel, Adam Pascal and Kerry Ellis, with a 100-person chorus, the Royal London Symphony, and a pipe organ.
"Anthem" - the last two lines have become one of my mantras
"I Know Him So Well" - the duet between the wife and the mistress
"Pity the Child" - when the bully cracks
This performance was aired on PBS/BBC and is available on CD and DVD. Well worth seeing, IMHO.