The term epic might mean different things to different people but to me these seem like epic type songs so basically just vote for your favorite. Pleaase dont start teaching me what u think epic means haha.
I voted for Stairway To Heaven, because I'm a mobile disc jockey (DJ) who has played the Led Zeppelin song more often than the others. In the 20 years I've been a DJ, "Master Of Puppets" by Metallica has never been requested at any events I've been hired to play for, but the song "Enter Sandman" is VERY popular with a wide audience and I can definitely say its one of the Most Requested rock songs of all time!
Master of Puppets would not be requested at that kind of thing simply because it is not an appealing song to people at some sort of party. Sandman is different because of its pop element that it has. Enter Sandman is my favorite song of all time so please dont think im bashing its credability but MOP i would say is more of an epic song