The whole episode when Lisa gets married is a play on Love Story

Related:

• Lisa is supposed to marry Hugh. The wedding gets cancelled and Rev
  Lovejoy says, "... this is terrible. And this never...
• A sign for Kent Brockman's TV station in the future reads
  CNNBCBS: A division of ABC Episode: 2F15 Lisa's...
• Lisa: Oedipus is the one who killed his father and married his mother Homer
  Argh! who paid for that wedding? Episode: Simpsons...
• Chief Wiggum: Ooh, and here, out of the mists of history
  the legendary esquilax, a horse with the head of a...
• Lisa: [breathless] Hello, I need "Ecosystem of the Marsh
  by Thompson. Librarian: The last copy was...
• Lisa: That's the book I need. You'll probably take forever with it
  too. Hugh: I can read faster than you. Lisa...
• Mr. Smithers, in the future, to a dead but cyrogenically preserved Mr
  Burns: Oh, Mr. Burns, we'll thaw you out the second...
• Lisa: Beautiful dinnerware, Mrs. Parkfield. Mrs. Parkfield
  Thank you, Lisa. They were made for the finest family...
• Lisa: Hi, Mom. Marge: Lisa! Hello. How are you doing in England
  Remember, an elevator is called a "lift", a...