1. ''I Will Always Love You'' 1992
The song that went on to become a defining highlight of Houston's career almost never happened at all. Originally, the then 28-year-old was slated to cover Jimmy Ruffin's early Motown hit ''What Becomes of the Brokenhearted'' for the soundtrack of The Bodyguard, in which she also had her first major film role. It was her costar, Kevin Costner, who suggested she take on Dolly Parton's plaintive 1974 country ballad instead. (Against the record company's wishes, Houston and Costner fought to keep the extended a cappella intro, and won.) Her gospel-tinged reworking of the song a towering showcase for the singer's phenomenal three-octave range was an immediate global smash, topping the charts in 16 countries, and spending a record-shattering 14 weeks at No. 1 in the U.S.
2. ''The Star-Spangled Banner'' 1991
Perhaps the most iconic, chills-inducing version of the national anthem ever rendered, it was also the only one to chart as a top 20 hit twice. Her powerhouse performance at Super Bowl XXV stirred the patriotism of a country in the midst of the Gulf War, and did so again in the wake of 9/11; in both cases, Houston donated her share of profits from the song to servicemen and women.
3. ''How Will I Know'' 1985
While it was first offered to Janet Jackson, the fifth single off Houston's debut album ended up being exactly the sort of buoyantly dancey hit hey there, sax solo! that the girl until then known primarily for stately ballads needed to be a true pop crossover star. And if you haven't heard the remarkable vocals-only version currently making the rounds online, go listen right now. No really, go. We'll wait for you.
4. ''My Love Is Your Love'' 1999
Many had already written off Whitney as past her career prime when she released My Love Is Your Love, her first studio album in eight years. But this gorgeously syncopated soul-pop lullaby featuring a sweet cameo (''Sing, Mommy'') from her toddler daughter, Bobbi Kristina rightfully went on to become her third-most-successful single ever, and redefined her for a younger generation.
5. ''I Wanna Dance With Somebody'' 1987
A spirited descendant of ''How Will I Know,'' this triumphant summer single met the gold standard of '80s pop, inspiring TIME magazine to crown her ''The Prom Queen of Soul.'' And the music video, showcasing a shimmying, bow-bedecked Whitney who just wanted to have some fun and ''feel the heat with somebody,'' became an indelible clip of the era.