Fallout: New Vegas players may choose to side with the NCR or the Legion, but can only choose one. Should I choose NCR or Legion?
You should choose NCR for more quests, and the Legion for evil roleplaying. The NCR offers far more quests, companions, and locations.
A Legion run is great for roleplaying, but you won’t get much more benefit out of it.
Quests | NCR or Legion
The NCR provides a much larger amount of side quests than the Legion offers. Including unmarked quests, the NCR offers a whopping 42 side quests for the Courier to cash in XP and caps on.
The Legion offers less than half. Including unmarked quests, the Legion provides 20 side quests for the Courier to complete.
Companions | NCR or Legion
New Vegas has 8 permanent companions: Arcade Gannon, Boone, Lily, Raul, Cassidy, Veronica, ED-E, and Rex.
All of these companions are compatible with an NCR playthrough. The only exception is Veronica, who will leave you if you don’t push back on the NCR’s decision to destroy the hidden Brotherhood of Steel Bunker.
On the contrary, many of these companions will not side with you during a Legion playthrough. Gannon and Boone will not stay as your companion as your Legion reputation rises, and Veronica will leave after Caesar forces you to destroy the Brotherhood of Steel bunker.
Lily, Raul, and Cassidy will allow you to side with the Legion. ED-E and Rex are non-human companions and won’t provide an opinion on the topic.
Open World
The NCR control a much larger swath of land in the Mojave than Caesar’s Legion. Operating in the center, East, Southeast, and North, the NCR gobbles up much of the land. They also operate within New Vegas and its surrounding area.
The Legion, on the otherhand, are mostly centered in the bottom right of the map. That means that as a Legion sympthaizer, you’re only going to be comfortable in parts of the map that are not often traveled.
If you play as a woman Courier, you’ll have a hard time joining Caesar’s Legion as a female. You can, but you won’t be able to participate in the Fort’s combat arena.
You’ll have a much easier time traveling through the Mojave on good NCR behavior. If you’re idolized by the Legion and the NCR wants to attack you on site, navigating the Mojave will be a much more cumbersome experience than the other way around.
So that’s the answer. You should choose the NCR for more XP, but the Legion for evil roleplaying.