Regardless of whether we each liked a particular movie, it's a year with many titles that have had some kind of lasting impact or are otherwise notable. edited to add some that I missed:
Among movies released in 1999:
Being John Malkovich
Fight Club
Star Wars: The Phantom Menace
Mystery Men
The World Is Not Enough
Green Mile
The Iron Giant
The Sixth Sense
Austin Powers: The Spy Who Shagged Me
The Matrix
Toy Story 2
Galaxy Quest
The Mummy
Man on the Moon
Magnolia
Office Space
American Beauty
South Park: Bigger, Longer, and Uncut
The Boondock Saints
10 Things I Hate About You
The Talented Mr. Ripley
The Blair With Project
American Pie