The reaper bot was a good start, but it wasn't until the Frogbot[1] was released that Quake bots really came of age.

[1] http://www.quakewiki.net/archives/botarea51/main/qbot7429.ht...

Side note: I regularly played against the Frogbot's author (who used the handle Frog) at LANs. He was reknowned for being the most analytical and "bot-like" player of our scene.