Actually, Taryn, 1776 is a one act musical, so there is no 1st act closer, in the sense that we're talking about. Maybe a production you did or saw placed an intermission, though that'd be a strage place to put it.
If you cheat and let the last 3 songs from the 1st act of Sweeney, no show can compare - no show has a last 15-20 minutes of act 1 like Sweeney Todd ("Pretty Women," "Epiphiny(sp)," and "A Little Priest"). "One Day More" is a great ender, as well, though a little by-the-numbers (then again, what isn't these days?). Others:
"'Till We Reach That Day" from Ragtime
"Light of the World" from Godspell
"Everything's Coming Up Roses" from Gypsy
"La Vie Boheme" from Rent
"Weekend in the Country" from A Little Night Music
I won't list "Defying Gravity" with the rest of them, but it is pretty good, though it's more a great moment than a great song.
"Who is Stephen Sondheim?" -roninjoey
"The man who wishes he had written Phantom of the Opera!" - SueleenGay
GO CARDINALS!!!