Megatron is at his strongest in "Transformers (2007)", in his original body after millennia of battle.
He transforms into a Cybertronian jet and sports a fusion cannon along with a lethal mace.
In "Revenge of the Fallen", Megatron is slightly weakened and rebuilt from scraps of a deceased Decepticon.
He now transforms into a Cybertronian tank but still wields his fusion cannon, along with a pincer claw on one hand.
In "Dark of the Moon" Megatron was much weaker as he had been heavily damaged previously.
He could transform into a rusty old truck and primarily fought using a double barrel shotgun.
In "Age of Extinction" Megatron takes control of a brand new body made by K.S.I called Galvatron.
He could swiftly transform into a K.S.I truck and had several in-built blasters, blades and missiles.
By "The Last Knight" Megatron had significantly modified his body into the form of a knight.
He now transforms into a military jet and wields a Sword- along with an arm-mounted fusion cannon and a flame thrower.