My favorites have to be Revolting Children from Matilda since its so fun and everyone is always so in awe of those kids up on stage giving it 200%. I personally consider that the closing number since When I Grow Up/Naughty Reprise is technically the curtain call. I also love Flying Away from Fun Home. It's so beautiful and makes me and most of the audience sob. Then I love You Can't Stop the Beat from Hairspray and then Find My Way/Finale from Legally Blonde. Both are just really upbeat, infectiously happy songs that I think perfectly capture the overall tone of both shows and close them really well.
Wow. Can't believe a post I started YEARS AGO has been revived! Haha. I stand by YCSTB, but right behind it in tone and spirit is the finale from its 'sister show' (Kinky Boots), Raise You Up/Just Be! Thank you, Cyndi for the gift of pure joy.
Book of Morman; Pacific Overtures; 1776; The Band's Visit; 9; South Pacific, My Fair Lady; King & I; Fun Home; Something Rotten!; Hello, Dolly; Fiorello; Chicago; Raisin; West Side Story; Mystery of Edwin Drood; Merrily We Roll Along