Nice try. New Vegas is objectively the better game. This reaches farther than simple "opinion" or predisposition towards either company. Anything Fallout 3 did, New Vegas did better, and in those instances where it's a matter of preference (such as playing on Hardcore mode) it can be toggled. More options -> objectively better, doesn't matter how you slice it.
The only argument you will be able to put forth that has any validity is that you don't like the New Vegas setting. That is personal opinion, and you won't find anyone arguing with you about your preference there.
Don't come in the thread with " Never understood the affection for New Vegas I found it buggier and less believable than F3 " , then when posters call you on it, you dance around with your nonsense above.