The Good Guys – AUTOBOTS

Optimus Prime, the Autobot leader who transforms himself to a blue Perterbit truck with red flame decals

Bumble Bee transforms itself to a Cheverolet Camaro, and the guardian of Sam

 Ironhide, the Autobot weapons specialist who transforms into a GMC Topkick

 Ratchet, the Autobot medic who transforms into a search and rescue Hummer H2

Arcee, female Transformers that transform into three motorcycles: a pink Ducati 848, a blue
Suzuki B-King 2008, and a purple MV Agusta F4

Mudflap and Skids, the twin Autobot infiltrators transform respectively into a red Chevrolet Trax and green Chevrolet Beat

Sideswipe, the autobot transforms itselft to a silver Chevrolet Corvette Stingray Concept

Jetfire, a Seeker and former Decepticon who transforms into a SR-71 Blackbird. His wounds and age have made him choose to become an Autobot

The bad guys – Decepticons
Megatron – The Decepticon leader, who transforms himself to a cybertronian tank

Soundwave, Megatron’s Communications Specialist, in the first movie it turned out to be the Blackout and Frenzy

Ravage, a minion of Soundwave that resembles a large one-eyed jaguar that transforms into a cybertronian missile – Sound wave variations starting from left, Frenzy, Blackout, Ravage

Starscream, the air commander who transforms into an F-22 Raptor

Sideways, a silver Audi R8 hiding with Demolishor in Shanghai, China until he is discovered by the Autobots

There are more of them,

Devastator – He transforms into a lot of construction vehicles