You never know what missed cue, funny turn of phrase or unexpected moment will send a "Saturday Night Live" cast member into laughing fits as they desperately try to stick to a bit -- but that's just the magic of live television.
Although the jury is still out on whether or not cast member crack-ups cheapen "SNL" sketches, you can't deny that in some cases, the break makes the bit (like with Bill Hader's "Stefon" or just about anything involving Jimmy Fallon). Whether you find them exciting or distracting, there have been too many memorable crack-ups in the show's nearly 40-year history for us not to stop and appreciate the best ones.
Check out 18 of the funniest crack-ups below, include two bonus videos featuring Phil Hartman and Chris Farley's best bloopers. Vote for your favorite moment and tell us which ones you remember the most in the comments!