The first game that I played in my life. (1999~2000)
I love this game in all aspects, the gameplay is good, the levels are fun, the star missions are creative at the most part, and the soundtrack OMG the "Dire, Dire Docks" song, so gracefully.
This is one of the games that I beat at least 2 or 3 times a year.
And also the mod community makes this game feel so alive nowadays.