Fallout is, quite simply, the closest any CRPG has ever come to the real thing. It is a singularly amazing game, the ultimate peak of the genre.
From a game system that's actualyl so faithful to the tabletop tradtion that you can actualyl play it tabletop, to a perfect balance of openness and direction, and with an unmatched freedom of approach, the kind of game where no two games are necessarily the same, simply because there's so many different ways you can do sometihng.
The writing is fantastic, black humor with a bend towards the greyer areas of morality, a wonderful counterpoint to the current obsession with hackneyed black-and-white morality made popular by games like KOTOR.
It's a masterpiece, pure and simple.