I know I'm three years too late, but I Want You (She's So Heavy) was the last song all four Beatles completed in the studio (edited and mixed and whatnot), but The End was the last song they recorded as a group.
Good quiz. Nice mix of easy stuff and harder stuff for the bigger fans. I've read a lot about them and still didn't know one or two, including the last one about the End. Very interesting piece of trivia.