Two: Piloted Shredder
Who is surprised that Piloted Shredder is on the list? Anyone? No one? Okay. Obviously Piloted Shredder is an extremely strong minion, being the bane of ranked players throughout Wild’s history. Shredder was one of the main reasons that players were looking forward to the Standard format, simply to be rid of it. For those of you who don’t know, the issue with Shredder is that it only loses two stat points to put a random two drop in play. While this random two drop can sometimes be awful and sometimes be amazing, it averages out to be approximately a 2/3 minion. This means that Piloted Shredder has the stat line of, on average, 6/6 for four mana. It’s also extremely strong against removal, since the two mana body will stick around. In fact, there are almost no good ways to trade positively with Shredder, without relying on randomness.
This one isn’t too much of a contest, Shredder is one of the best cards in the game, regardless of rarity. He is also a very low cost minion, meaning he works well in any deck. I would take shredder over almost any class common, almost every time.