Simon Helberg chooses his favorite Big Bang Theory episodes

To commemorate The Big Bang Theory series finale, cast members were asked to select their favorite episodes. Butterflies, Dungeons & Dragons and a grand romantic gesture made an impression on Simon Helberg (Howard).

The Werewolf Transformation

A change in Sheldon's routine forces him to re-evaluate his entire life, when his barber is sick. Meanwhile, Howard rethinks his decision to go into space after astronaut training.

What Simon said: "I ate a butterfly. That kind of line only comes along maybe every four years like the Olympics. And like the Olympics, it deserves a medal. The progression of the scenes with Howard going through utter hell were so perfectly constructed. And the "butterfly" scene is one of the few instances where we only did one take."

The Closet Reconfiguration

To open or not to open? When Howard finds a letter from his father, he's forced to confront his past. And Leonard and Penny throw a grown-up cocktail party at the apartment.

What Simon said: "The writers brilliantly crafted this story climaxing in a kind "Wait Wait...Don't Tell Me" where each one of Howard's friends tells him a version of what is in the letter his father left him after abandoning he and his mother, while only one of them is true. It beautifully highlights how close this group of friends truly are."

The Love Spell Potential

When the girls' trip to Vegas falls through, the guys invite them to a Dungeons & Dragons date night that causes Sheldon and Amy's relationship to take an unexpected turn.

What Simon said: "I had such a fun time doing that slew of impressions in the D&D scene. The audience was so pumped to hear all of those voices come out of me. I don't always love to do impressions because it can feel a bit like a party trick but it felt authentic to Howard's character, and ultimately doing voices and impressions became somewhat of a trademark of his."

The Romance Resonance

Sheldon makes a major scientific breakthrough, but he feels it may haunt him for the rest of career. Meanwhile, Howard makes a grand romantic gesture to Bernadette, which causes Penny to put more effort into her relationship with Leonard.

What Simon said: "Kate Micucci and Riki Lindhome (aka Garfunkel & Oates) wrote a brilliant song that is the most incredible blend of humor and emotion. Some of my favorite moments in the show is when the comedy and the humanity of these characters are in perfect harmony and this was a prime example of that."

The Positive Negative Reaction

The gang learns Bernadette is pregnant and celebrate by singing karaoke. Meanwhile, Wolowitz freaks out over the pregnancy announcement and becomes convinced he must make more money to provide for the baby.

What Simon said: "The opening scene with Melissa was one of my favorites of the whole series. The rhythms and structure - from discovering the pregnancy test to pure elation to utter terror - is another instance of truly fantastic writing. And Melissa is the most open and wonderful scene partner anyone could ever have."