it's clear that the best maps have always been the ones that had been heavily modified to the extent that it really wasn't what treyarch expected. mods such as nazi_zombie_420 and zombie_realism had been my favorites since they came out. nazi_zombie_castle is another one of my favorites down to the point that it was extremly glitchy to the extent that i managed to get to where the zombies spawn without dying and even to the roof of the main building. maps with mods put in to them were obvious like ZCT mod 2 in nazi_zombie_subway. subway is the most (or almost) famous map you'll see.