Summoning- Nightshade Forests (and just about any song of theirs)
Aeternus- As I March (laid-back "epicness", the melodic intro is the best ever)
Arghoslent- Branding the Peon (catchy "epicness", the way the song gets faster as the song progresses is amazing)
Burzum- Beholding the Daughters of the Firnament (simple structure but exerts such a monumental, reflective "epicness")
Immolation- Unholy Cult title-track (best epic death metal track ever; the atmospheric guitar and drum section at the end is truly memorizing)
Sacramentum- Blood Shall be Spilled (the section with the triumphant guitar harmonization near the end really kicks ass everytime)
At the Gates- Within (simultaneous tremolo guitar and violin section near the end produces such a memorable epic outro)
I could go on and on... many, many great epic songs out there.