Well if there's two criteria, being unique and being able to solo, then the only result is paladin. Clerics aren't unique and neither class can solo well, but clerics need a raid drop, Dawnstar, to solo (undead) effectively whereas paladins only need a Guk drop, Ghoulbane, to do so.
There's a side argument to make in that you have limited time, and pallies may not be overly welcome in groups with their penalty and inability to tank until mid-levels.
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