Durin's Song is a very good card to include in a Dwarf deck or any deck with a Dwarf hero. Whenever you need a quick stat boost, Boom. It's notable that the boost is to all stats, and that it lasts until the end of the round, so with some sort of readying; you could get double duty out of it. Very good filler.
Action: Choose a Dwarf hero. That hero gets +2 , +2 , and +2 until the end of the round.
In many-pillared halls of stone
With golden roof and silver floor,
And runes of power upon the door.
The Fellowship of the Ring
Khazad-dûm #4. Leadership.
A seriously OP card in any kind of dwarf deck. Like Wandalf said, with readying, a dwarf hero can become almost invincible for a round. Notably, it's also only 1 cost. The art and the quote are also pretty great.