During Saturday Night Live's 40th anniversary special, a whole musical number was devoted to actors breaking character. While breaking is considered unprofessional in some circles, SNL's cast members have turned it into supplemental viewing, some a few too many times. (looking at you, Fallon.)
YouTube channel KateMcKinnonTV recently bottled this magic into two compilation videos, featuring members of the current cast as well as older casts. There's ol' Breaking Jimmy and some more classic clips with Chris Farley, Gilda Radner, and Will Ferrell, as well as that alien abduction sketch where Ryan Gosling couldn't stop laughing.
H/T Hello Giggles