It's tough to recall a presence more iconic than Whitney Houston's, and that undeniable impact is doubled in her videos. It doesn't get much more dramatic than Houston belting out the bittersweet "I Will Always Love You" in-between scenes of her and Kevin Costner from The Bodyguard, and the heartwarming “Greatest Love of All” video has her embracing her mother, Cissy Houston, to tear-jerking effect.