The Big Bang Theory is full of cute, romantic moments, and among all them, there's one that I'm specially in love with: Howard and Bernadette's anniversary.
On the day of the anniversary, something goes wrong at the lab, which compels Bernadette to stay there in order to avoid any possible biological contamination. That would ruin the date since she's unable to leave the lab. And that's exactly why Howard decides to bring the date to her instead. :)
The scene shows Rajesh, Penny, Leonard, Sheldon, Amy and Howard -at the piano- ready to give Bernadette the best anniversary gift ever: 'If I Didn't Have You', a wonderful song composed and performed by the one and only Howard Wolowitz -leading voice and piano- along with all his friends -backing vocals-. To me, the best aniversary gift ever, and one of the most special moments in The Big Bang Theory. Enjoy yourself! :D