The loser tends bar at the league party: taking orders, mixing drinks, and enduring cocktail requests invented specifically to be annoying. Tips go to the pot. A muddled drink is sent back on principle even when it's fine.
Budget note: this one costs nothing but dignity, which makes it a strong pick for leagues that would rather spend the pot on the champion than on the loser's downfall.
Seen in the wild: fantasyfootballunlimited.com