Knuckles, it's very equally matched here but Sonic is new to the power, as Knuckled has had the power of strenght his whole life, so more time to practice and power up. So I say Knuckles. Plus... I'm a huge Knuckles fangirl XD
I don't know... Knuckles breaks rocks with his fists but werehog... uh... his powers are questionable. Sometimes he pulls very light looking lever, punches eggman robots too many times that what they should take, and ... i don't know.