There is no agree to disagree here. This list is definitive and there can be no discussion about order of games or omissions. It is perfect and complete, but just since I'm curious, what games would you guys have included on the list?
Took the FPS genre to a new level and is widely regarded as one of the greatest games of all time, full stop. Half-Life is also of course is also the basis for the wildly popular Counter Strike mod turned full retail game which enjoys a loyal following even today.
Effectively introduced the genre to the world and my introduction to gaming induced motion sickness. While maybe not as popular as its successor, Doom, it definitely was the foundational title for the genre.
Brought on-line multiplayer FPS goodness to the masses by being the premiere shooter on Xbox Live. It paved the way for other critical FPS successes on consoles such as Call of Duty 4: Modern Warfare and Gears of War.
Recognizing the rabid popularity of deathmatch gameplay Quake III: Arena eschewed a single-player story mode all-together focusing totally on deathmatch style games versus human players or "bots". Q3A's release and laser focus on multiplayer gameplay coincided with growing professional gaming communities such as Quakecon and the CPL, signaling the maturity and prominence of the genre.
Essentially brought the FPS concept of death matches from basement LAN parties to the mainstream by utilizing the Nintendo 64's 4 controler/4-way split screen set up. I lost a full summer of my life to this game.
