The Half-Life era (98)
While it could be said that the single player campaign had its faults due to a short play-through time and frustrating situations, it was extremely satisfying for those that held a desire in methodically resolving puzzle-like levels and hostage situations. The multiplayer portion carried its own weight and then some by pitting two teams of 8 against one another in a game of metaphorical cat and mouse.
The Tom Clancy's games today: The Tom Clancy titles (and man are there a lot of them) have seen a huge wave of success in past years and there is no sign of them slowing down. Titles typically follow the tried and true formula of strategic/stealth action mostly based around fictional world conflicts influenced by modern times and technology.
A more anime-esque style on both the graphic and audio fronts along with being one of the first FPS's to implement cut-scenes in-game was certainly the initial step in originality. To match that, not only did the game have a healthy blend of original weapons and standard on-foot FPS gameplay, it allowed players to wage war in several 100' tall Mobile Combat Armor units.
Shogo today: A planned sequel for Shogo was eventually cancelled and since then Monolith has moved on to work on other successful franchises like No One Lives Forever and F.E.A.R.
While the original Half-Life had plenty of potential as a standalone game, the way Valve embraced modders paid off more than they could have ever imagined. Roughly seven months after the games release came a downloadable modification that would change everything. Counter-Strike effectively pit terrorists against counter-terrorists and introduced a slew of new realistically modeled weapons, tactile-minded maps and scenery with an appealing set of game modes which continuously drew in gamers, making this the most played online FPS to date.
Half-Life today: Perhaps one of the most active franchises to this day, the series has received several sequels (including the episodes) and expansion packs, most of which have been received gracefully by gamers. Half-Life is the most glorified first person shooter along with the original Doom.