What is the best spec for DM runs as a paladin?

By DM, presumably you mean Dead Mines.....really, that run is so low-level (it is the lowest level Alliance instance in the game) that it shouldn't matter much what "spec" you are, since you only have up to 9 talent points to spend before you start runing Stockades, so your "spec" really doesn't necessarily do much for you at those levels, y'know? Now, if you were talking about Dire Maul, that's a different story. :)