Yeah, who knew James Stewart could play drunk so well? That scene constantly comes up during TCM's Scene It game and it always makes me laugh. For me, Nick and Nora. Although the scene where Nick Jr. makes his father drink milk was pretty great, the rest of that sort of... wasn't.
Gary Cooper and Fredric March in Design For Living, when Gilda leaves them both alone in the apartment. That one had me rolling with laughter. They were both so funny. "I refuse to be silly."
On the other end of the spectrum for Fredric, A Star Is Born was so painful to watch. "His work is beginning to interfere with his drinking." The scene where he interrupts her speech? He earned that Oscar nomination, for sure.