My favorite game evar. You play as JC Denton, a new agent for the United Nations Anti Terrorist Coalition, who has been genetically altered and augmented with nano machines turning him into the perfect killer. It's your first day on the job, and terrorists hijack a shipment of Ambrosia, the vaccine to a deadly virus called the Grey Death which plagues most of the western world.
The graphics are blargh, but it makes up for that with good art direction, and after a while you forget to notice the shortcomings because you're too caught up with the great plot, the great music and the amazing gameplay. This game really makes you work your noggin' in the fighting. On Realistic difficulty, you can't just run in and gun down an MIB, three commandos and a security bot without some serious firepower (i.e. a GEP gun) and some luck, or a good grasp of strategy and stealth.
Followed closely by Planescape: Torment
The game is practically a novel with over 80,000 words of written text. It has amazing writing, great characters, and a unique and great setting. My favorite video game story. Anyone who likes good storytelling in video game format should check this out. It's a ***** to get your hands on, but I strongly recommend it.
The plot? You're an immortal amnesiac who wakes up on a mortuary slab with no memory of who he is. Turns out you're in a city called Sigil, which is located at the center of the multiverse. You go out and adventure and collect companions such as a floating skull, or a succubus who has a brothel where people can quench their intellectual thirsts rather than their physical lust, or a suit of armor that want to destroy all chaos while trying to figure out your identity and why you're immortal.
And it asks the great question: What can change the nature of a man?
The combat sucks, but who cares? Most of the EXP rewards comes not from killing epic creatures, but from things like unmaking people by pointing out the logical flaws in their existence. That's right, you unmake someone by proving that they cannot exist.
Oh, and the spells in it are AMAZING graphically. Only other game I can think of that involves a one minute long cut scene for a spell are the Final Fantasy games, and those are summons, not spells.