Parade magazine and celebrity gossip website omg! teamed up for the pop culture poll.
Houston, 48, slipped under the water in her bathtub after taking a cocktail of marijuana, cocaine and prescription drugs while she was getting ready for an appearance at the 2012 Grammy awards in Los Angeles in February.
The tragedy in February beat Kristen Stewart cheating on her "Twilight" co-star Robert Pattinson with filmmaker Rupert Sanders into second place in the poll.
Tom Cruise's split from Katie Holmes in June comes third, and the top five is rounded out by 'Jersey Shore' reality star Nicole 'Snooki' Polizzi's pregnancy and Demi Moore's stint in a rehabilitation clinic.