Barney explains the magic of February thirteenth, or as he calls it, "Desperation Day."

Penny tries to patch things up between Leonard and Sheldon when they are having a fight, but ends up making things worse!

After Marshall and Barney have an argument, Robin and Lily try to figure out what type of alcohol will get them in the right mood to reconcile.

When Penny dislocates her shoulder, Sheldon brings her home from the hospital and tucks her into bed.

Howard takes a moment in the tub to fantasize that Katee Sackhoff from Battlestar Galactica is in the tub with him. As it turns out, she has some advice for him.

American adult animated sitcom "Family Guy" has been nominated for and won many awards. It continues to air new episodes, going on its fourteenth season.

Leonard finally tells Penny how Sheldon saved his life and broke the elevator at the same time.

When Penny returns from visiting her family in Nebraska, Leonard is happy to see her. Sheldon, however, is much less welcoming when he learns that her family has the flu.

Penny invents a quiz to find out whether Sheldon or Leonard is smarter, which only reveals that both of them are completely uninformed about popular culture with the exception of Star Trek.

Jimmy Fallon can't believe he's at the White House on the Fourth of July. Watch part of his stand-up performance from that evening in which he does impressions of ten other comedians!

In this week's Lightning Round, Neil Patrick Harris and Billy Eichner take to the streets to find out how New Yorkers feel about the end of the series How I Met Your Mother.

Watch Academy Award winner Julianne Moore ambush innocent tourists with her acting ability in the hopes of making some tip money in Times Square! Forget Elmo, Spiderman and the other random characters tourists take pictures with in New York, this is Julianne Moore!

The United Kingdom voted to leave the European Union, and it looks like it may not be an especially smooth transition. John Oliver goes over the decision on his show "Last Week Tonight."

Barney never fails to impress the group with the lengths he'll go in order to get a woman interested in him.

From time to time, we give celebrities a chance to read some of the mean things people tweet about them. We extended that same offer to our Commander in Chief, who happily agreed. This is an all President Obama edition of #MeanTweets.