Five: Pit Fighter
Pit Fighter is one of the most underrated cards in arena. For five mana it trades positively with almost every other five drop, while having enough health to often take a few hits from smaller minions. It may not splash onto the field like some other cards, and it won’t turn around a game that you’re losing massively, but if you can get it in play it will cause your opponent no end of trouble.
Because of his incredible stat-line, Pit Fighter works well with every class. It is a good tempo drop on turn five, while also being a strong draw later in the game. The only notable weaknesses it has are to Fireball, or extremely fast decks.