Re: How I Met Your Mother: Barney and... (Spoilers ahead...)
^Yeah, I remember that one. Part of me feels like there's an episode with the whole gang in the theater, despertely trying to stay awake during the show because its important to one of them. But I could also be imaginging it/mixing it up with another sitcom. But I feel like in eight seasons, there HAS to have been an episode where they go to a Broadway show, or see a play or something of that nature...
That's exactly the episode already mentioned. Lily forces everyone to attend her bad play and Barney takes revenge by inventing his own, even worse play, and has the sit through it.
"Chewie, we're home.."