Watching Transformers 2007 and ROTF I made these observations about Transformer weapons. 1. Most prefer projectile weapons. Whether bullets or missiles they use them. In Optimus' riffle it seems to be a designed for compressed air to shoot out the bullet. Megatron in 2007 a railgun of a sort. Others seems to be chemically explosive driven. As to where they get bullets Transformers likely grow them like regenerative metal armor. 2. Directed energy weapons. Transformers seem to use two different types. Orange hot one and the blue variety. I'm just going to speculate that the orange one that BB uses is plasma based as it melts right though Brawl. The blue one which Megatron uses could be particle based as it blasts Optimus flying during the forest battle of ROTF. 3. Melee weapons. Barricade , Blackout and Grindor has a spinning cutter weapon for melee. Ratchet also uses one. Megatron in his new form has an arm that is used to slash and stab. Scorponok stabs with its tail and drills.Optimus has his energon swords and hooks. Optimus can also throw his sword at an enemy. Sideswipe has his swords. Rampage uses his arms as whips. 4. Electromagnetic based weaponry. Several instances we see Transformers use electromagnetic based weapons. First was Blackout in attack at Qatar with a stomp. Jazz can magnetically attract objects such as disarming the Sector 7 agents. Ironhide and Starscream demonstrated EMP. 5. Transformers as missiles. Perhaps most devastatingly was orbital bombardment by transformers themselves as seen with the Fallen's attack on the aircraft carrier. 6. The Fallen is unique from others as he seems to have gravity manipulation ability. Though the Primes have a similar ability he could be stronger than they are.