System Shock 2...dare I say not quite as good as its predecessor?
I did a zero-PSI, zero-exotic (because most of the exotic weapons appear to suck) Navy run for this first playthrough. Exploding things with my brain is something for next time. Kind of odd that, despite maxed standard/heavy weapon stats (and just-short energy), my trusty assault rifle easily outperformed the BFG Fusion Cannon on "DEATH", and puny "better than Citadel's model my posterior" Laser Rapier. Even the grenade launcher barely outdid it. (Of course, when it comes to killing yourself, the Fusion Cannon prevails at reducing you to a cloud of radioactive mist.)
Oh, and "a basically linear final third ending in a single risible cheap-gag cut-scene undercutting the whole thing!" Ouch. Not as bad as Bioshock's, but Looking Glass never made that mistake.
I'd rate it below System Shock (1), Deus Ex (the only one), and Fallout (1). But it makes Half-Life look horribly oversimplified. Scavenging for precious shotgun ammo by having to pick up and unload the dropped, broken weapons of your dead foes is suitably tense, and it maintains scarcity with everything but health brilliantly.