Personally, I think House is by far the best choice. Yes Man just throws everything back to immediate post-war anarchy (for absolutely no benefit to the Courier, no less). The Legion would at least bring peace and stability in the short term, all while destroying pretty much all of the pre-war tech and infrastructure that House managed to preserve before collapsing or at the very least fragmenting after Sallow is gone (either via coup or death by brain tumour). The NCR, while a clear 2nd best, are corrupt, bloated and spread way too thin. They can't even keep their core territories free of raiders, much less bring civilisation to their more unruly frontier provinces. Meanwhile, House has more access to and knowledge of pre-war tech than any faction in the wasteland, save perhaps the Enclave, as well as the means and the intention of actually using it to uplift the rest of humanity all the way up to pre-war society, as opposed to hoarding it for the sake of hoarding it, or using it to wipe out almost all sentient life.
If you ask me, the choice is very clear.