The best Xbox 360 game of 2008.
If you were to buy one game for the the 360 right now, it should be Fallout 3. I bought this game on day one, not expecting to play this game for that long - Gears 2 was coming out the next week. However, I was completely wrong, and to this date I have played over 100 hours.
The game is set in 2270 (I think) in a post-apocalyptic nuclear setting in Washington D.C. The bomb dropped in 2077, and people stay in fallout shelters (Vaults). Nobody ever enters or leaves the vault, or consequences will happen. When you start the game, you are in the perspective of a newborn baby. This is basically the tutorial and character selection portion of the game. When your dad leaves, the overseer sends guards after you to interrogate you, so you make a dash out of the vault. One thing that I hated about the game is that once you leave the vault, the story and pacing and all of that stuff just stops. The main quest becomes really boring, and the main quest doesn't pick up until around one-fourth of the way through. However, this is remedied by the amazing side quests. There are about 15 main side quests, and all of them have a unique story that gets you invested in the world. That is what really made the game for me.
The gameplay is another great factor. You are set i a first person view, and you shoot (and hit) your way through hundreds of enemies. However, the shooting part is hard to get a hold of because the shots aren't consistent. The VATS system helps this by pausing the game, selecting a body part, annd shooting it. You get experience for killing enemies, doing quests, and doing productive things, such as lockpicking and terminal hacking. You also get more experience for setting the game to the higher diffuculties, and less experience for lower difficulties.
The graphics may look bland and ugly, but you'll appreciate the game later. You can see so far off, that it feels like a real world. Also, there are details that would have not made any impact, yet shows how much Bethesda cares about their game. There are a bunch of glitches though. There are sound glitches where the sound doesn't match the correct visuals. Also, there are graphical glitches like people floating. Some glitches happen in side quests where the person you need to talk to doesn't respond or do the right action.
Even though there are a bunch of bugs and some pacing issues, the side quests' story, the atmosphere, pretty much everything made the game a whole new experience.
Note: I loathed Oblivion, even though I loved this game. Mail me if you want to know anything about the game.