Dang it, I always miss these!
Anyway, my previous employer (a company of about 150 employees) had monthly "pep rallies" to try to boost morale (the majority of the employees were glorified telemarketers). The middle and upper managers would create skits, songs, etc., usually based around a theme.
Some highlights:
A cross-dressing wedding gag that also included someone in blackface, wearing an afro, and attempting to speak "jive"
"Surprise" visits from the VP's brother dressed in a gorilla suit, handing out comp time coupons in .25 hour increments if you answered questions about the history of the company correctly.
A 4-man quartet who wrote parody covers of famous songs, with lyrics related to sales goals. (Michael Scott was literally a parody singer-songwriter!)
Most recently, they tried to make a video of the entire office staff dancing go viral by tweeting it at celebrities. No joke.
In fact, they tried to participate in every viral/mob video trend that came up.
So glad I'm no longer there.