The Godling purely because even though he's had a fluke this year with Gangster Squad, he's been upping the ante for like two or three years now.
Tatum and The Rock also deserve a lot of credit, both for their output (multiple movies a year) but also the fact they were able to give their careers a second life after their fifteen minutes seemed to run out.
Speaking of second lives, Matthew McConaughey in my opinion deserves to share first place with The Godling. Once he decided to stop doing those bullshyt rom-coms and become a serious actor again and he's been dropping nothing but heat. Magic Mike, Killer Joe, Bernie, all crack, plus I've heard he done did it again with Mud.
And Mud brings me to Michael Shannon (he stars in it as well in all other movies by Jeff Nichols), who would fill up the Top 5 alongside the four just mentioned. The man's steady on his way on becoming the most intense actor working today.