Top commanders: Storm Cast many cheap spells in a single turn, then finish with a spell that has the storm keyword
Virus Beetle just reprinted for Standard counts too
Many cards have Shift or abilities that rely on certain types and numbers of characters being in play (we're looking at you, Seven Dwarfs)
Along the way, there are plenty of obvious winners: cards that become pro tournament staples, others that skyrocket in price due to rarity and usefulness, and everything in between
(Each in the mana costs of permanents you control counts toward your devotion to black.) Creature - Zombie Warlock Color tag templates(None) Harvester of Souls Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.) Whenever another nontoken creature dies, you may draw a card
Traxos, Scourge of Kroog is another card thats seen a lot of Commander play lately, and for good reason