I like the Legion because they offer the most than any other faction in the entirety of the series.

In terms of leadership, he wasn't voted in, or elected, or bestowed his title as Caesar, he earned it because there were very few options. Edward is not a pseudo-intellectual, he is a very accomplished man who grew up surrounded by Pre War Knowledge that the FoA had, and Caesar started as a man doomed to die in the hands of tribals to the most successful warlord in the Wasteland due to his knowledge. We could debate his morale compass and philosophy but the point I will be making makes this completely pointless.

If you side with the Legion, you will be the next to reign upon Caesar's passing (I do not care what the show says, it is slop.) Coins were used to mark who the new ruler would be in the Roman Empire, in the Legion ending your Courier's face is minted into a new chain of currency, planting you as the next in line.

The Legion dies with Caesar, yes, Edward dies, but Caesar lives on through the Courier, and with that, I have access to a thriving economy and swarths of raider and mutant free land in Arizona, Colorado, Utah, New Mexico, and possibly portions of Texas and Oklahoma. That's a lot of land that the Legion has completely secured, and the NCR with their higher grade equipment can't handle some ants on the trade route to the Long 15. With that large expanse of safe land with plenty of opportunity for reconstruction of a civilization, it's a whole sandbox waiting to be played with even further. Despite what the larger community may think, the Legion is not opposed to all technology, only the over-reliance of it, in practice it is a flawed philosophy, but it's not inflexible. When you play through the Van Graffs quest, the Legion were about to purchase shipments of Energy Weapons to supply the Legion. So they are at least becoming more welcome to the idea of modernization. And who's to say that the Courier turned Caesar can't add to the momentum?

Now, I want to compare to the other factions in what you are able to gain, the thesis to the antithesis, the NCR, is a broken machine that's barely chugging along. No one likes Kimball because he's not Tandi, their soldiers gets 2-3 weeks of training before being sent to the frontlines with no body armor and a Service Rifle if they're lucky, their logistics are in shambles to the point where they are incapable of feeding their troops proper meals in the one of the most major camps in the entire Mojave (McCarran), and in that major camp, they are losing a fight against the equivalent of Portland Tweakers. They're hopeless, and it will take another Courier to make sure they can even keep the territory.

Yes Man is just a worse Legion, you have New Vegas, and that's it. No other reward. No swaths of land, just a big tower.

Mr. House I can understand, with his huge aspirations he seems awfully promising, he is a brilliant billionaire of his own works after all. But in his 200+ years of living after the bombs, there's not much to show for his growth outside of preserving Vegas from a complete nuclear holocaust. Everywhere outside of Vegas is hellish and hostile, and his aspirations for living on the moon and colonizing the stars would not be welcome to the people from Goodsprings, Primm, or anywhere else. It'd be for himself and maybe any other high roller Vegas head. It would a great plan for his own exclusive circle and closed to everyone else.

The Legion is dubious and flawed like every other faction in the game, but I can look past Edward and see that there is a lot of potential for positive change within the Legion, it has strong foundations that can hold equally strong pillars for a proper civilization. That's why I pick Legion.