I don't agree with everything they advocate, nor do I agree with all of their ideals, but, in my opinion, I root for the Legion

I think they seek the betterment of mankind through self-discipline, self-respect, self-control, and loyalty

I don't agree with their making of slaves or their misogyny, but I respect their mindset towards abstaining from chems, alcohol, prostitution, reliance/dependency on technology; they also seem to value physical fitness and treating one's body as though it were a temple

The Legion possesses good morals, but they are often taken to the extreme and misguided. I fear their ruling, however, would degenerate into survival of the fittest

I think of what Easy Pete said concerning the NCR. Similar to the Legion, they believe they are doing the best for people as a whole, but like the Legion, they force you to be a part of their plans whether you like it or not. They appear to take a lot from those under their control, and they look out for themselves first before anyone else - plus the corruption

Mr. House is the ultimate fat-cat, materialistic, capitalistic, sociopath in my opinion. He shows not the slightest concern for others; focusing instead on his own wealth, and business enterprises. He strategically disregards people like pawns in a game or like rungs on a business ladder to accumulate further wealth and/or property. Only the wealthiest are able to rub shoulders with him; those unfortunate to lack in wealth are casually swept aside, as witnessed by those evicted from Vault 21

Yes Man grants you total control over Vegas, but this option also descends into anarchy. I believe this can be a good choice if your heart is in the right place and you're truly determined/committed to unite people. It comes down to what sort of person you are (?). You can either live by hedonism, or you can devote yourself to altruism. The power lies with you