Classic!
Even though I never really got to the point where anyone else - except myself - thought I was any good, it was great fun. I mastered the fine arts of bunnyjumping before signing off for good, after having struggled with that for a long time.
My all time favourite map was DM4, with the teleports, the lava, and the confined space. It was a blast! Truth to be told, that map was so great that I eventually excelled in it, not that that did me any good, seeing as they still kicked my ass in all other maps .. All in all, it's a classic that everyone that enjoys fps games definitely should try.