When I'm starting a new playthrough I'm always going for the sole hero, who's gonna rescue the wasteland/commonwealth whatever. Only at later times I sometimes switch to a normal scrapper or so, exploring the world map and not giving too much about main story, just living a normal life like everyone else. But in fact I never played the Yes-Man ending in NV and probably not going to do that. I just can't think that a simple Ex-Courier could rule over the Mojave, Caesars Legion or NCR are definitely better choices for that.

I don't really like any kind of overarching story that essentially goes "You're special because of X" I personally think it's a bit cliche, that's what I liked about Dragon Age Origins, there wasn't really anything special about you, you just end up taking the lead.