I would agree, btw, that some similarities exist strongly between Anabaptists and Orthodoxy.
And I'm glad to hear of mainline distancing themselves somewhat from PSA.
This question is impossible to definitively answer though, because it runs across a blanket of areas of belief. If it were very narrow and specific, it might be possible to determine who is "most like" the Orthodox on a particular point. But when you include a range of considerations,. everyone diverges, in different ways and to different degrees.
In some things O you might even see more similarities between some Pentecostals with Orthodoxy, compared with other Protestants, and I see no one mentioned them, because they are very different in so many other ways as to overshadow similarities.
It's really a complex question. Still one worth asking, and the discussion is good.
![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
. But just not one that can be definitively answered.