In some ways, maybe my favorite of the old-school DOOM games. Maybe it's the tight level design compared to some of the weaker spaces in DOOM 2, maybe it's the (comparatively) added emphasis on story, or maybe it's simply that the formula was so tried and true at this point that they couldn't do much to screw it up. Whatever it is, 64 is an essential member of the DOOM lineup and I had an absolute blast playing through it to see all the secrets and references it had to offer.