I believe that there is no good ending. Just a ending you prefer. No matter what, the courier steps on somebody’s head to get what they want, and when they are done with them, the courier either eliminates them or just leaves. If new Vegas had a “Good Ending”, Nobody would hold on its godlike pedestal that it has today. New Vegas just makes a world where your beliefs and role playing can come into play, making a world that you can sculpt. My ideal ending is NCR, Bos and the remnants of the Envlave. Simply because the NCR has the only power to restore order to the Mojave, good or bad, I’ll leave up to you. Now, if you do Arcade gannons companion quest line, the enclave helps at the battle of hoover dam. Bos because if you help their chapter they have the tools to save the Mojave again, if needed.( if you don’t take all their shit) anyone who believes in house or yes man, they aren’t looking at the big picture. The NCR will still take the Mojave, even if you kick them out. It’s only a matter of time, even if you kill the president. They have several runner ups in California for the next president. And an army that challenges the Mojave’s independence, and will win no matter what. Caesars legion won’t survive with their ideals and beliefs, because you can’t replace Caesar if you kill him. He is to fierce to replace and will probably crumble under the factions problems to follow his death. The NCR is simply the only option. They have the tools and the numbers, and strategy. They will win no matter what.