SPOILERS ON THIS COMMENT.
It's one of my favorite series (I'm not a big fan of the movie) all time, I don't think there's too many animation pieces that match it even today, about 13 years after its release. The characters are appealing, the storys are very fine, the animation is awesome and Yoko Kano's soundtrack is a killer. "Tank" and "Bad Dog No Biscuit" are unforgettable.
The construction of the cast, the whole banding together thing each episode after the last, till the disbanding, lefting again Spike and Jet alone, was a great idea, wrapping it all in one big story arc. I have this friend of mine that hates science-fiction and japanese animation, and she was just in love with this show.
By the way, director and creator Sinchiro Watanabe is a name to pay attention: he was also the director of Detective Story, the noir animation at the Animatrix selection; co-directed Macross Puls and in 2004 released Samurai Champloo: not a dieselpunk story by any chance, but a samurai story with several and crazy pop visuals and references.