Hey I've just started a new character and I'm having a bit of a hard time deciding whether he should join the NCR or side with Yes Man. Basically what I'm going for is a sort of Chaotic-Neutral frontiersmen who lives for the open air (think John Marston in Red Dead Redemption where he's at the end of the era he loves but won't admit it,) and believes people should be allowed to decide for themselves without an overarching government. However at the same time he also has a strict moral code which lines up, to some extent, with the NCR. :/

Either way I'm planning on just thinking that no matter who he sides with he ends up heading for the Mid-West to escape whatever form of government arise.

Chaotic Neutral? Yes-Man. Definitely Yes-Man. NCR is pretty strongly on the Lawful side.

Eh, go down YesMan or NCR first then nearing the end turn a 180 and side with the other one.
Maybe cause first he wants freedom for everyone, but as he goes down the Yes Man path he starts to ponder on whether or not the people of this region are capable of governing themselves, then it finally clicks for him that it's not the best option and he tries to make peace with NCR to make sure that there is a form of government to guide it's people.
Vice versa for NCR then Yesman.

Gabriel are you a mind reader? That's sort of what I was thinking already, but I'll see what other people suggest.

I usually go with NCR purely because they're the lesser evil. Yes Man is a good concept but everything would be plundered into chaos as soon as New Vegas was independent. Mans natural greed and jealousy would overrule the opportunity they had, factions like the Followers of The Apocalypse would be crushed by the overwhelming violence on the strip and in Freeside. The NCR do have their upsides, and many downsides too, but they're the side I tend to swing with here, they have the potential to be good if they were nudged in the right direction by a certain protagonist.

However in terms of gameplay, I agree with Gabriel, do all the Yes Man quests you can, and before you trigger "Don't Tread on The Bear" side with them for the end.