Champion of the Parish
 
I'm going to make a controversial argument here. Despite the number of one-cost creatures with two or more power, none has yet obsoleted Isamaru. Isamaru always has two power and always costs one mana, no more. When you don't have a specific tribe to build around, or a trick like Thatcher Revolt or Gather the Townsfolk (much less Parallel Lives), and you just have to destroy as many faces as possible as fast as possible, you pick Isamaru. But if you do, you pick Champion of the Parish, and in the right deck it's far from out of the question for him to reach the stats of an Eldrazi.
 
Constructed: 4/5
Casual: 4/5
Limited: 4/5
Multiplayer: 4/5
EDH/Commander: 4/5

CoTP
 
Eh. Humans. :shrugs: it gets big. I don't care. It's more of the usual pedestrian crap that magic players seem to dig. (potential) Big power despite a complete lack of anything else going for it. Tarmogoyf syndrome. Fun times.
 
Constructed: 2
Casual: 2
Limited: 2
Multiplayer: 2
Commander [EDH]: 2