As others have pointed out, New Vegas has a better main story. In fact not only the story of Fallout 3 is a bit "meh", but if you stick to the main quest, you

As others have pointed out, New Vegas has a better main story. In fact not only the story of Fallout 3 is a bit "meh", but if you stick to the main quest, you can finish the game pretty quickly. And tunnels. Lot of metro tunnels That said, you can wander around the wasteland and find a lot of nice subquests and hidden nuggets. In this regard, F3 really looks like Oblivion with guns, since in my opinion that game had the same exact issues (lame main story, beautiful side quests). NV's DLCs are also better in my opinion.