Doing "objective" comparisons, I think the three strongest perks are medic, local leader, and critical banker. Maxing out medic apparently makes stimpacks and radaway FIVE times more effective, which is nuts. I have heard reports that local leader enables settlements to generate large amounts of passive income. With eleven possible settlement locations, you can get unlimited money without any type of cheating. Maxing critical banker allows you to crit something three times in a row, even a legendary deathclaw probably won't last long taking that kind of damage.