One of the first epic songs I recall from my youth was "Rime Of The Ancient Mariner" by Iron Maiden. Not in the sense of EPIC, but "epic" as in long poem. It's rare to see an artist/band actually perform an epic song live, even if they do have one on an album. Probably because the lyrics aren't repetitive, the song is hard to remember, or the fans just don't like it. Hence, it seems those epic songs come few and far between.
I would consider the following an epic song. This is probably one of my favorite songs from some of the latest stuff by Green Day. I know I've mentioned it before, but hey, it's my blog. Deal with it. 
(A better quality live but non-embeddable version is here. And the official video is here.)
What songs do you consider "epic"? Or how about EPIC?
Until next time...
gary duke commented on February 18, 2010 at 6:40 am:
nice way to start my morning, i love green day, thanks
Urspo commented on February 18, 2010 at 8:56 am:
Dear me
I remember "The Rime" being a bit more low-keyed when we read it in High School.
Erik Rubright replied to Urspo on February 18, 2010 at 11:52 pm:
It's amazing what a little background music will do to an old epic poem. It makes one wonder what Beowulf would sound like.
Cb commented on February 18, 2010 at 9:52 am:
I have decided that I DO like Green Day.
Erik Rubright replied to Cb on February 18, 2010 at 11:53 pm:
Because of this?