Nuclear holocaust never played so well!
Graphically, this game is pretty good, with fairly steady frame rates and a few moments of sheer breathtaking beauty. Obviously, the game sometimes suffers from minor visual glitches, with games like this you take the good with the bad, but it is rarely enough to ruin your immersion with the game.
The audio is always snazzy and sounds like an explosion in the distance to a shot from your trusty hunting rifle sound crisp and true. Even when you are alone in the sewers, the steady drip of irradiated water and the hissing of far off ghouls will add to the feeling of a dangerous post apocolyptic world.
However, these aspects pale into insignificance when compared with the fantastic gameplay. Bethesda really pulled out all the stops when creating Fallout 3, resulting in a game where exploring feels rewarding and exciting. Do you want to follow the storyline, find your errant father and ignore every other location? Go ahead. If you want to roam around for a bit, feel free. Over every hill is another possibility, on one playthrough you might find a wasteland doctor scrapping with a deathclaw and on another in the exact same location you'll find a drug dealer ambling around, waiting to sell his wares.
To describe this as a mature, post apocolyptic Oblivion does a disservice to Fallout 3, as it deserves to stand alone as a fantastic role playing experience and a marker for all future Bethesda projects. In case you couldn't tell, i cannot state how much i recommend this game, buy it!