Some will remember Whitney Houston for her successes — millions of albums sold, a record seven straight No. 1 singles, the first female artist to debut on the charts at No. 1. Others will remember her for her troubles — her drug abuse, her rocky marriage to Bobby Brown. But we'll always remember her for her music and her one-of-a-kind, undeniable voice that turned mere songs into cultural benchmarks. Three years ago today, Feb. 11, the world-renowned singer tragically died in a Beverly Hills hotel. In her honor, BET.com counts down her 40 best songs, each a testament to her once-in-a-generation talent and spirit.