1: There's always more to do the second time around. One of my favorite things is how many paths you can choose, every path has at least a bit of moral conflict, drama, a storyline. So that in itself gives it depth.
2: The style gives me a very nostalgic feel. The whole western shoot 'em up feel brings me way back, so in a way, this game makes me feel... at home.
3: So many new toys to play with! Now, believe me, I've played almost every Fallout game out there, and this is ALMOST the best one yet, second only to Fallout 3. And one thing that I absolutely love is how much content they add from game to game. In Fallout 3 you find a vast and extensive variety of weapons, clothing, armor, food, Chemical Enhancers(Chems), but it really doesn't even compare to the deadly armory that you're supplied with in New Vegas.
4: The voice acting and dialogue options are so much better. In Fallout 3 they had a pretty nice little system (But the voice actors kind of sucked) for the dialogue system, it was pretty clean cut and tidy. But with this one, they rounded off all of the jagged edges, got new, better voice actors, and rounded it up to create something beautiful.
The one thing that makes me angry about this game is how buggy it is.
So take it from a serious gamer with no life, you should really get this game.
So fast forward a few years and now I have such severe dry skin on my back that I am driven to distraction during the day, can't fall asleep at night, and sometimes even wake up crying or screaming because of the itching. Instead of messing around with cheap lotions that never work, I went right for this magic stuff. I had only put it on my back for 2 days when the itching calmed, and now, one week later, ALL the itching is gone, there is NO flaking skin whatsoever. And my skin doesn't even feel greasy after.