I was surprised there wasn't a thread for this game. It's amazing. I'm playing it on the PC and it's eating up a good amount of my hours lately. I've currently played through the Main Questline as well as The Pitt, Operation Anchorage (that was amazing), and Point Lookout. I've got many many mods for it (as the PC version IS the game. If you bought it for anything else, facepalm. NOW)

Why is the PC version the best? Third Party Mods. They make the game playable endlessly. I could go on about third-party mods, but I'll let others figure it out for themselves. Google "Fallout 3 Mods" and click the first link. explore and enjoy. ^^