A lot of people will be familiar with the
System Shock 2 Rebirth project but this
article at The Random Gnomes' Random Lair (nice name) has a guide to several mods to bring
SS2 up to "2K7" standards. Here's the intro, which aptly describes why
SS2 is so good:
System Shock 2 is better than Deus EX, more elaborate than any of the Thief games, scarier then Resident Evil and quite frankly more engrossing than the whole porn DVD collection of planet Earth. In short, it's a fantastic game. A brilliant one too. I mean, it's even got itself a Gamespot retrospective. Unfortunately though, what with being almost retro, its graphics have started to age and their late nineties 3D engine simply doesn't look that scary anymore. Oh, and WinXP, minor gameplay and sound problems have also managed to creep up.
More information.