There are comics who work for decades and never produce anything of value, and then there are comics who are brilliant but die tragically before the world really has a chance to see the full extent of what they really could have done. In fact, many of the best comedians that ever lived are now dead! Here are 12 comedians whose died too young and whose potentially brilliant careers were cut short by tragedy. From Bill Hicks to Robin Williams, these comedic geniuses left a lasting impression on the world of laughs.

01 of 12 Bill Hicks Bill Hicks at the Laff Stop in Austin, Texas, 1991. Angela Davis/Wikimedia Creative Commons Bill Hicks was perhaps the most influential comedic voice that was tragically cut short. The comic—who should have been a household name and would have been had he not passed prematurely—was a brilliant satirist and darkly honest comic who could eviscerate any given topic with the ferocity of a chain-smoking attack dog. Influencing an entire generation of comics for both better (Patton Oswalt) and worse (like Denis Leary, who some say lifted Hicks' act wholesale) he was and still is one of the best comedians to ever perform stand-up. Hicks died of pancreatic cancer in 1994 when he was only 32 years old. Though he died too young, his legacy lives on in the comics he inspired.

02 of 12 Lenny Bruce Fulton Archive One of the godfathers of modern stand-up comedy, Lenny Bruce fought for free speech and pushed the limits of what a comedian could say and do on stage—and came up with some classic stand-up routines in the process. Toward the end of his life, Bruce wasn't so funny anymore as he was consumed by court cases, often turning club appearances into live readings of legal documents. Bruce, who had been a drug addict for some years, was found dead of an overdose in 1966. He was 40 years old. Comedy would not be the same without his contributions, short-lived as they may have been.

03 of 12 Greg Giraldo Kristian Dowling/Getty Images Like a number of comedians on this list, Greg Giraldo seemed to just be hitting his stride when he died suddenly of an accidental overdose of prescription medication in September of 2010. The Harvard-educated comic had two brilliant albums to his name— "Good Day to Cross a River" and 2009's "Midlife Vices." He was also becoming quite a comedy star, thanks to his killer appearances on the annual Comedy Central roasts. His comedy style was smart and dark and bitingly acerbic; he was, to put it simply, one of the best comedians of his generation.

04 of 12 Mitch Hedberg Scott Gries/Getty Images Mitch Hedberg is that rare comedian whose popularity and success came largely after he died of a drug overdose in 2005. He was the master of the absurdist one-liner, and his comedy became a hit with college crowds and comedy fans alike. It wasn't until after he was gone, though, that the mainstream public became aware of his genius, finally discovering his 2003 album "Mitch All Together." A second live stand-up album, "Do You Believe in Gosh?" was released posthumously in 2008. Hedberg was on his way to becoming one of the biggest, most influential comics of his generation, and his death at age 37 was considered a tragic waste of talent—especially by college students.

05 of 12 John Belushi Photo by Getty Images John Belushi was a comedy icon when he died in 1982, thanks to his breakout status on "Saturday Night Live"—where he was one of the original "Not Ready for Prime Time Players"—and his iconic role in the 1978 film "Animal House." He was one of the first "wild men of comedy," whose addictions and hard-partying lifestyle defined him almost as much as his need to be funny. Belushi was only 33 when he died of a drug overdose, robbing the world of one of its most gifted comedic performers.

06 of 12 Bernie Mac Scott Gries/Getty Images Bernie Mac spent years paying his dues in comedy clubs before finally getting national exposure in the early 2000s, thanks to his participation in the "Original Kings of Comedy" stand-up tour—and the Spike Lee concert film of the same name.​ From there, Mac became a huge star, getting top billing in feature films and starring in his own long-running Fox sitcom, "The Bernie Mac Show." He had a rapid-fire, take-no-prisoners approach to comedy, often focusing on how difficult life can be but always in an honest, funny way. The comedy world suffered a great loss when Mac—who suffered from the autoimmune disease sarcoidosis—died at age 50 of complications from pneumonia, at perhaps the height of his career.

07 of 12 Chris Farley SGranitz/WireImage/Getty Images Chris Farley idolized John Belushi, so it's no surprise that the similarities between them are uncanny: like Belushi, Chris Farley started out doing sketch comedy at Chicago's Second City. Like Belushi, he went on to become a breakout star on "Saturday Night Live" before transitioning into popular comedy films like "Tommy Boy". And, like Belushi, Chris Farley lived too hard and was addicted to drugs and alcohol. When he died in 1997 of a drug overdose, he was 33 years old—the same age as Belushi when he died.

08 of 12 Sam Kinison Comedy Central Sam Kinison was the first heavy-metal comic—from his long hair and hard partying to his trademark screaming delivery of"Oh OOOOOOOOHHHH!" His style of comedy was a huge influence on the generation of comedians who came after him. A former preacher, Kinison's routines often became sermon-like: he drew you in and made you listen to his gospel of comedy. He also had major substance abuse problems, but amazingly it wasn't the drugs or alcohol that killed Sam Kinison. He was killed in a car accident in 1992, just six days after getting married.

09 of 12 Robert Schimmel New York Times Like the hero of "Night of the Living Dead," comedian Robert Schimmel survived tremendous hardship only to be tragically killed by a random occurrence. He beat cancer, survived a heart attack, and lived through major marital difficulties (divorcing his wife multiple times, then marrying the best friend of his oldest daughter before separating from her, too). A true comedian, he mined all of that pain in his brutally honest, dark stand-up routines. It's all the more tragic that Schimmel's difficult life was cut short when he died of injuries sustained in a car accident in September of 2010.

10 of 12 Andy Kaufman Photo by Fotos International/Getty Images Andy Kaufman was one of the comedy's greatest oddballs, from his iconic performances on "Saturday Night Live" lip-synching the theme to "Mighty Mouse" to his supporting role as Latka Gravas on "Taxi." He went on to perform as an alternate personality—a nightclub singer named Tony Clifton — then took a late-career run as an amateur wrestler who only wrestled women. Seemingly all of Kaufman's comedy ventures were offbeat, anti-comedy stunts. Though he lived his entire life as a health freak, Kaufman was diagnosed with a rare form of lung cancer at age 34 and died just one year later. Who knows what the next phase of his comedy might have been!

11 of 12 Patrice O'Neal Patrice O'Neal at the 2009 Just for Laughs Chicago Festival. Barry Brecheisen/Getty Images Known for his brutal honesty and ability to riff for hours on stage without any written material, Patrice O'Neal was a brilliant comic respected by all of his peers. In other words, he was a comic's comic. While a lot of comedians claim to be inspired by Richard Pryor, O'Neal is one of the few comics who could honestly be said to be Pryor-esque. He talked about sex and race in ways we're not used to hearing people talk, not even in the comedy club. When he died in 2011 of complications from diabetes, the comedy world suffered an enormous loss. O'Neal was a real genius and told it like it is.