Reanimation
Put something enormous in the graveyard early, then bring it back cheaply.
Casting a twelve mana creature honestly takes most of a game. Discarding it and paying three to return it takes two turns. The deck is a small number of huge threats, a reliable way of getting one into the graveyard, and several ways of pulling it back out.
Not this one?
Leave empty for no limit. Cards you own do not count.
Commanders for Reanimation
Ordered by how often they are played, with the ones you own first.