I played this game a shit ton as a kid, and I can't get over the fact that it released little over a month before the American invasion of Iraq in 2003. IIRC, the first American mission features a cutscene of tanks running over the Victory Arch.
The storyline revolves around America and the PRC fighting a witldwide terrorist front called the "Global Liberation Army".
Yes, it's my favourite RTS. I used to play this almost every day before I had internet at home. As a kid I didn't realize how racist the depiction of China and GLA were lol.
I also like how they added factions in Zero Hour. Added a lot of variety. Plus, the mods are pretty great (Contra, Shockwave).