4. Heath Ledger
When heartthrob Aussie Heath Ledger first came to public attention in the late 90s, it would have been easy to dismiss him as just another pretty face in Hollywood. Fast forward to his amazing acting prowess in such films as Brokeback Mountain and Dark Knight, however, and nobody was questioning his acting prowess. In January of 2008, the star (who suffered from notoriously bad insomnia and had been known to resort to drastic measures to get some sleep) was found dead in his New York apartment by his housekeeper. The cause of death was found to be an accidental overdose from a toxic combination of prescription and over the counter medication.