I assume that you mean for us to comment on 'non-traditional' heroes that do not jump out as powerful (ie - not Dain, Spirit Glorfindel, Legolas, Eowyn etc).
Some heroes that I use that others may not are:
a) 'super cool hero' Beorn (as he was refered to by Mathew on the progression series): amazing early game hero that you can use to tank attacks and not worry about defense or attack for a couple of rounds letting you get out a bunch of questers and make good progress
b) Boromir: Like Brandon has often said, the tactics version is a beast! in some quests (ie - massing at osgiliath) where action advantage is paramount he cannot be beat. Partner him with Loragon or Spirit Glorfindel to avoid the threat problem
c) Dunhere: with the new dagger that has come out and various methods to push enemies back into the staging area, paring him with Faramir can make a interesting deck that can work well in certain quests