Obsessed with gift-giving etiquette, Sheldon buys multiple bath item gift baskets of varying sizes. He intends to match the value of Penny's gift exactly, but after receiving the napkin, he realizes no commercial gift is enough and gives her every basket he bought.
While Sheldon obsesses over gifts, Leonard deals with professional and romantic jealousy when a handsome MacArthur grant-winning physicist, David Underhill, starts dating Penny. Interesting Perspectives [S2E11] The Bath Item Gift Hypothesis
In an interview about the episode, producer Steve Molaro noted that the impact of the gift exchange was palpable even during the first run-through with the cast. Obsessed with gift-giving etiquette