De_piranesi was official even. And then wasn't there a de_museum with giant dinosaur skeletons. Incredible visuals for the poly's, but the connectivity just wasn't there. Sm0lders (de_rotterdam) had a terrific bank map called cs_robbery that started repeatedly getting the shaft from cliffe around when CS went retail.
And don't ever call cs_siege an example of good gameplay. That thing chokes worse than Greg Norman. There's a download of it in the entry for "grandfather clause" in Encarta. It would never ever ever have stood a chance of becoming official if it were new in even the beta 5's of CS.