Supreme EXU Legionnaire
INCREDIBLE work, especially for a DOOM 2 MOD (still blowing my mind here). Genuinely terrifying in many areas, and the sound design in particular is astoundingly good.
Superb custom Blood mapping, right up there with the retail levels and in many cases surpassing them. Super fun, creative, well-thought-out and balanced levels. You can't possibly miss this out if you enjoy Blood (and who that's played it doesn't?)
Can't imagine playing STALKER without OGSE.