Samsara (SAMSARA-V0.3666-BETA.PK3)

Samsara allows you to play as a formidable complement of classic FPS heroes and either duke it out in deathmatch or slay monsters alone and in co-op. The intent was to provide something like Marvel vs. Capcom for Zandronum. Term eventually discontinued development when he moved on to a new project to drive all the Doom players crazy - Demonsteele - but Kinsie of Reelism fame eventually took up maintenance of the mod so that you can use the same package in both GZDoom and Zandronum just as easily as you can use all of the heroes in any of the idtech1-derived games.

Strife: Absolute Order (SABORD.WAD)

I love Strife, so it's cool to see that a few crazy people make WADs for it. Absolute Order was originally going to be a much larger project, but it's clear that Adam "Khorus" Woodmansey decided to finish the project as it was rather than languish due to disinterest. So, here's a short episode for the most neglected child of the Doom family (unless you count HACX). The plot is pretty simple. Even with the death of the entity at the end of the original game (uh, spoilers I guess), outposts of the Order remain. You're not the Strifeguy, apparently, just an agent of the front who's been sent to loosen tyranny's dying grasp on the world.