Doomsday Engine - Doom 2 PC Gameplay Short
CAUTION! Unsuitable for minors!
You just can't beat the visceral and cathartic endorphin release that is Doom 2! Currently, it is most playable using the Doomsday Engine with high resolution texture and model packs. It's all free, so long as you have your original Doom 2 WAD file.
Doomsday also caters for other versions of Doom, and also Heretic and Hexen.
You know you want more ... so go visit http://dengine.net/ :)