Naruto, One Piece, DBZ's, and Bleach O_O I'm not even close to done with Bleach, so I'm just skipping episodes here and there *shakes head in disappointment* (its mais than 300 episodes with 15 seasons -sub, not dub yet-! Agh, too long! lol)
Definitely Detective Conan, it even has 2+ hora long episodes amor the show, im a mystery fã so its best show ever to me then ive seen Bleach (think the animê ended), stopped watching naruto after Pain died the war thing is bs.. Fairy Tail&Detective Conan.. And Rurouni Kenshin (I dont watch naruto fillers so I havent seen too many episodes theres not that many)
Maria-sama Ga Miteru which is 44 episodes of pure loveliness <3 Plus it had DVD exclusive shorts but I don't really count those as episodes since they're Omakes. K-ON! is close behind at 41 and also has shorts.
The longest animê I have seen is Yu-Gi-Oh! Yu-Gi-Oh! Duel Monsters has 224 episodes Yu-Gi-Oh! Capsule Monsters has 12 episodes Yu-Gi-Oh! GX has 180 episodes I've seen a few episodes of 5D'S and ZEXAL as well Then there is also Yu-Gi-Oh! The Movie: Pyramid of Light and Yu-Gi-Oh! 3D: Bonds Beyond Time
So all together that is over 416 episodes plus two movies.