It's hard to believe that Britney Spears' debut album, ...Baby One More Time, was released this week in 1999.  Twenty years later it's still a bop. There are plenty of other hits from '99 that have shown plenty of staying power.

Seriously...try NOT singing along to these:

1. Britney Spears -- "...Baby One More Time"

2. Christina Aguilera -- "Genie In A Bottle"

3. TLC -- "No Scrubs"

4. Backstreet Boys -- "I Want It That Way"

5. Smash Mouth -- "All Star"

6. Eminem -- "My Name Is"

7. Ricky Martin -- "Livin' La Vida Loca"

8. Lit -- "My Own Worst Enemy"

9. Mandy Moore -- "Candy"

10. Blink 182 -- "All The Small Things"

11. Lou Bega -- "Mambo No. 5"

12. Kid Rock -- "Cowboy"

13. Len -- "Steal My Sunshine"

14. Shania Twain -- "Man! I Feel Like A Woman"

15. Jennifer Lopez -- "If You Had My Love"

I'll take "Things That Make Me Feel Old" for $600, Alex.