Over 22,222 downloads within ten years of release! DXN - Deus Ex: Nihilum is a First Person Shooter mod set in an alternate Deus Ex continuity. It features made-from-scratch original content while also extensively featuring material from the UNATCO Born mod (used with permission from fender2k1, UB's project leader) and Deus Ex: Revision (2011 build - used in accordance with the mod's license).
This is a simply superb mod that takes what Deus Ex got right and then augments the hell out of it with an exoskeleton of dazzling, modernized visuals, innovative and unique game design, sing-in-the-car good music, and a tight gem of speculative-fiction story that does justice to the original (and that is some hard justice to do!)
Personally, aside from a full-blown Project Eternity-style, kickstarter initiative afforded the laser-guidance of Warren Spector, heuristically retooled by Harvey Smith himself, and infused with Sheldon Pacotti's sci--fi writing gems, I think Deus Ex: Nihilum is tough to beat for a Deus Ex 1 sequel.