I usually prefer a Legion ending, besides the NCR being corrupt its almost an exact replica of pre-war America, still holding many of its flaws. House actually puts it best, he states that the fate of democracies "lie outside the windows", meaning the NCR is basically on the same trajectory as the old world governments. Caesars Legion although flawed works around this of course by rejecting technology and most production which would prevent something as devistating as another nuclear holocaust. Not to mention, up until you meet Caesar, i don't feel as if any of the other factions really recognize you as the asset you are. House just assumes your still in his employment, the NCR and Crocker are really just looking for someone to clean up their mess in the Mojave, and Yes Man just seems a bit bland to me, lifeless. But when you meet Caesar he makes a point to tell you why your important to his cause, citing how you take bullets to the head, then proceed to track down your shooter across the desert, then stride right into the Lucky 38 and send the Strip's top boss fleeing, Caesar seems to understand the Couriers true importance unlike the other factions. Plus, fighting profligates with tribals dresseed as neo-romans on a giant dam is pretty amusing lets be honest...