This game (for PC; $54.99) was five years in the making, and every minute appears to have been well spent. The graphics and physics of how objects move in Half-Life 2's world are by far the most realistic ever to grace a computer screen.
As you wander the streets of City 17, the alien-controlled police state your character Gordon Freeman is attempting to subvert, you have to rub your eyes to realize you're not actually visiting an East European capital. And check out the mayhem you can cause with Gordon's gravity gun, which sucks in any metal object, then fires it out at will.
The only catch: you will need a pretty powerful PC (one with a 2-GHz processor) to enjoy Half-Life 2's full experience.
Ideal for: Trigger-happy adventure seekers