Minutemen. With my character they can aim to help the most people, including non-ferals and synths and the occasional non aggressive super mutant. Whereas the BoS would not help those groups or would actively attempt to exterminate them which I am not ok with, and the Institute is too dumb to realize what it is they’ve created which makes them slavers, which I am also not ok with. The Railroad needs to stay underground so they can actually help escaped synths though with the Institute gone I don’t suspect they will be needed nearly as much, if at all. I don’t mind still helping them through the Minutemen either way.