The magic is gone
I came into Fallout: New Vegas with a love for Fallout 3; with its 40's music, its exploration, and its dialog trees. I even love the bad parts like its unfair ending and its janky physics engine. Fallout 3 nailed the concept of open world better than any other game. You really can do anything right from the start of the game. There are areas that will kill you if you don't level up first, but it's fun discovering those areas and revisiting them once you've leveled up.
In Fallout: New Vegas, the magic is gone. The exploration aspect of the game is still there, and the game still has its charm, but overall Fallout: New Vegas is inferior to its predecessor for me. The awesome 40's music has turned into a very limited selection of bad 50's music. The janky physics engine is even more janky to the point that it can mess up the experience. And the game's leveling system has been "balanced" so that you can no longer wander around as a god, dealing death to whomever you choose with impunity. (C'mon! When will game companies learn that after I've played their game for 40+ hours and fully leveled up my character, I no longer want to be required to shoot people in the head 10 times to make them fall? One shot should suffice, even with the weakest gun.)
I've restarted Fallout: New Vegas three times now, trying to bring myself to like the game. I just don't. I'm so disappointed!