Im not sure if this belongs in here, but i was thinking about it and well it is already up to 238 eps and no where close to being finished. Now i dont know everything about anime but this seems like alot more then most series. Oda plans are writting 300 more chapters (approx) plus there will be filler arcs inbetween. so this will add up to over 500 eps.
I know Detective conan has alot but im not sure. Also Dragonball z had 290 or so eps.
if anyone could help answer my question id be grateful ^.^