well, instead of posting all of these other songs that others have posted, I'll save time by saying I agree with the obvious choices.
However, everyone should listen to Coheed and Cambria's "Mother Superior" (not the acoustic version, the full band version's instrumentation is just epic sounding as it builds to the end). Get past the voice, and any dislike for the band, it's an obvious throwback track. One reviewer even stated it's Co&Ca's Stairway to Heaven. Even as a big fan I cannot say it is in the same league, but it's a farm team of it and has many attributes that put it close.