With the exception of ascendancy (and possibly the indy game on newgrounds No Time To Explain), doom had the best music of video game history - certainly the best MIDI music. That's one of the reason doom was so memorable and great. None of the music, for none of the levels, were songs that were annoying to get stuck in my head. They were always the sort of thing where I could hum them when running and almost like magic I would be able to cover a mile in under 5 minutes. There are at least 4 of them, which are so unspeakably epic that it's a wonder they all came from the same people. Whoever was the genius behind them. "Phobos Anomaly" from D1E1 was probably the best of all, followed by "The Pit" from Doom 2, "Tower of Babel" from D1E2, and then of course "Hangar" from D1E1, but maybe I'm biased in favor of that one just because it's where the legacy all began. Other notable memorable ones that come to mind were "Gotcha" and "Idol of Sin" from D2 and a few from which I'm not sure the map they came, but many of which are here. Trying to order them in descending awesomeness is difficult, because any one of them blows away almost any music from any other video game I ever played. They should have worked some of them into the 2005 movie somehow. Good god, has it been that long since the movie, how could that be.
But anyway, this largely does it justice. I like listening for the first few seconds and thinking back to the levels they come from when I recognize them.