Derevi, Empyrial Tactician (BLC) $13.85 Probably the best Bant card, Derevi, Empyrial Tactician was printed in one of the earliest Commander precons and has been popular ever since
If it doesn't get taken out by a removal spell as soon as it hits the table, it can win you the game in no time
If you don't have a commander, Command Tower's ability produces no mana
Lulu, Stern Guardian This three-drop 2/3 lady and legendary can turn attackers to you to get a stun counter to stop them from untapping or swinging elsewhere
This will be a negative for decks with payoffs that specifically want you to draw cards, but on the other hand your foes won't be able to target your draws
Three mana to lock a creature down is usually a playable card