When I saw the question I immediately thought DB rows and wide grip BB rows. My rear delts are pretty good and I've never really targeted them. However, I work hard on the DB rows.
After the DB row challenge with all those reps my rear delts were the one muscle with the most DOMS.
I've done a lot of deads and I've never noticed any soreness in the rear delt area afterwards.
Cliffs.....DB rows FTW.