The 2008 first person shooter, Bioshock (PC, XBox 360, PS3), was/is popular with a lot of people, but I doubt anyone would say it's consistent in it's quality. After a certain point in the game, it does go downhill, and the end battle is bad and betrays the atmosphere and feel of the game.

But someone has written up a small article about how they wish the game would have ended, and it's fantastic. If you like Bioshock even a little, then you most read this, it's very good indeed.

http://www.pentadact.com/2009-04-15-ending-bioshock/

Of course, if Bioshock had been released ten years earlier, or even only five, then PC owners might well have eventually have gotten this ending, as modders would have been very keen to explore and enhance Rapture. Granted making the above ending would entail a lot of work, but dedicated (teams of) modders have aimed higher, and have sometimes delivered.

Sadly of course, Bioshock was unmoddable (well, it was moddable, but since the SDK was never released, it's far harder to mod than a game with it's SDK made publically available), as by then the now modern attitude of "Don't give the players the tools to make their own levels, instead we will make the addon levels ourselves, and charge for them" that means that almost every modern FPS is now all but unmoddable. And I HATE it. The Half-Life games, Unreal Tournament games, Doom Games, Quake games, Thief games, etc, all have exponentially longer playing lives due to the mods that exist for them, thanks to hardworking (and unpaid modders).

Even the Deus Ex series has fallen victim to this no-SDK-for-the-fans attitude, the first game (released in 2000) did. It's two sequels? Nope.