Leonard Nimoy
We all of course know Leonard Nimoy for his iconic role as Mr. Spock in the Star Trek franchise. He was a long time cigarette smoker, and he died of a lung related disease at age 83.
Chris Penn
Brother to the very famous Sean Penn, Chris was a talented actor in his own right. He had roles in films such as The Wild Life, Reservoir Dogs, Footloose, and The Boys Club. Initially doctors believed he died of heart disease, but it was later revealed that a number of prescription drugs including promethazine, codeine, valium, and morphine were found in his bloodstream as revealed by his toxicology report. He was only 40 years old when he died.