#1 - Countdown to Extinction 8.81
Season 1 - Episode 12
Starscream is going to destroy the Earth and take the energy from the explosion to rule the Universe. The Autobots and Decepticons must team up to stop that disaster.
#2 - The Key to Vector Sigma (2) 8.62
Season 2 - Episode 40
The Decepticons acquire the key that will give them access to Vector Sigma. After using Vector Sigma, they find the key is also capable of making organics turn into machines. Megatron prepares to use it against Earth and the Autobots will need new allies in this battle, but their creation will come at a high price.
#3 - The Rebirth (3) 8.59
Season 4 - Episode 3
After capturing Daniel and Arcee and acquiring the Plasma Energy Chamber key, Scorponok and the Decepticons make their way to Cybertron. The Autobots head after them, but Spike and Cerebros stay on Nebulos and come up with a strategy to use a Hive city as a weapon against Scorponok. Meanwhile, the Decepticons and Scorponok begin to threaten Earth and it is up to the Autobots and their allies to stop them.
#4 - Traitor 8.50
Season 2 - Episode 5
Failing to cause a divide between the Decepticons and Insecticons, Mirage's mind suddenly becomes enslaved and he is used by them in a plot against the Autobots.
#5 - Enter the Nightbird 8.43
Season 2 - Episode 6
The Decepticons send the recently stolen Nightbird on a mission to steal an informative chip from the Autobots.
#6 - A Prime Problem 8.42
Season 2 - Episode 8
The latest Decepticon plot to destroy the Autobots involves the creation of an Optimus Prime duplicate. They hope this imposter will be able to convince the other Autobots he is the genuine article and will lead them into a chasm that will destroy them.
#7 - Megatron's Master Plan (1) 8.38
Season 2 - Episode 15
Megatron and a politician team up to slander the image of the Autobots.
#8 - Megatron's Master Plan (2) 8.35
Season 2 - Episode 16
While Megatron and Shawn Berger enjoy Decepticon Day in Central City, Spike tries to find video evidence that proves the Autobots are innocent!
#9 - B.O.T. 8.33
Season 2 - Episode 49
During a battle, the Protectobots finish off the Combaticons, with the exception of Swindle. Megatron orders Swindle to reconstruct his destroyed comrades or else a bomb in his head will go off, destroying him. As Swindle works to complete this task in time, three students get a hold of Brawl's personality component and use it for their science project, B.O.T., with disastrous results.
#10 - The Immobilizer 8.32
Season 2 - Episode 2
Wheeljack's new invention, the Immobilizer, is capable of rendering any Transformer immobile for a short time. Once the Decepticons get their hands on it, they modify it and begin leaving many Autobots immobile.
#11 - Dinobot Island (1) 8.24
Season 2 - Episode 3
Proving to be a danger even to their own allies, the Dinobots are sent away to train on a recently discovered island in the hopes that they will learn how to effectively work together. The island, however, is far from ordinary as it is populated by dinosaurs. Meanwhile, the Decepticons make advances toward the island so they can acquire it's natural resources.
#12 - The Ultimate Doom (3) 8.24
Season 1 - Episode 10
The Autobots on Cybertron evade capture and work toward finding a way to counteract the effects of the hypno-chips. Meanwhile, Optimus Prime leads the remaining Autobots in a battle to put an end to Megatron's plan.
#13 - The Search for Alpha Trion 8.23
Season 2 - Episode 32
Elita-1, leader of a group of female Autobots causing trouble for the Decepticons, is captured and used as bait to lure Optimus Prime into a deadly trap. However, Elita-1's strange time manipulation technique saves him, but leaves her close to death. Her only chance for survival lies in Alpha Trion.
#14 - Child's Play 8.18
Season 2 - Episode 30
The space bridge accidentally sends several Autobots and Decepticons to a strange world in which they are no bigger than toys.
#15 - The Rebirth (2) 8.15
Season 4 - Episode 2
Daniel and four Nebulans join with five Autobots to battle the Hive, but the Hive decide to do something similar with a group of Decepticons. Meanwhile, Optimus Prime goes to Vector Sigma to find out the whereabouts of the missing Autobots and encounters an old face, learning the answer and what must be done.
#16 - The Insecticon Syndrome 8.12
Season 2 - Episode 13
The Insecticons become extremely powerful after they consume an energy source. They enslave every Decepticon except for Megatron. The Decepticon leader and the Autobots will have to team up to return the Insecticons to normal.
#17 - Desertion of the Dinobots (1) 8.11
Season 2 - Episode 19
Both Autobots and Decepticons are facing tough times as they are in need of the element called Cybertonium. The Decepticons quickly get as much as they need, but the only way for the Autobots to get it is to rely on the Dinobots, who have been unaffected by all this. However, the Dinobots have been getting annoyed with the Autobots lately and leave them.
#18 - Microbots 8.11
Season 2 - Episode 11
The Decepticon ship that shot down the Ark has been found and Megatron manages to find a component containing great power. With this power a danger to everyone, Perceptor, Bumblebee and Brawn shrink down and journey through Megatron's body to get it away from the Decepticon leader.
#19 - Quest for Survival 8.08
Season 2 - Episode 28
On the way to Earth with a type of insecticide to use against the Insecticons, Spike, Bumblebee and Cosmos encounter Morphobots. They get away just fine, but they inadvertently take Morphobots along for the ride.
#20 - Starscream's Brigade 8.08
Season 2 - Episode 46
Failing to topple Megatron, an exiled Starscream plans his revenge. He uses World War II era machines and five personality components to create the Combaticons, which prove very powerful in their Bruticus form.
#21 - The Key to Vector Sigma (1) 8.07
Season 2 - Episode 39
The Decepticons acquire the Key that will give them access to Vector Sigma. After using Vector Sigma, they find the Key is also capable of making organics turn into machines. Megatron prepares to use it against Earth and The Autobots will need new allies in this battle, but their creation will come at a high price.
#22 - Ghost in the Machine 8.07
Season 3 - Episode 17
Starscream, in Scourge's body, attempts to complete three assignments for the damaged Unicron in exchange for getting a new body.
#23 - The Five Faces of Darkness (1) 8.04
Season 3 - Episode 1
While everyone continues to rejoice in their victory, unknown assailants capture Ultra Magnus, Kup and Spike. After being told by an alien, a group of Autobots suspect the Decepticons are the culprits. But when they arrive at Charr, they find the Decepticons in no shape to pull off a kidnapping, meaning another is responsible.
#24 - Dinobot Island (2) 8.00
Season 2 - Episode 4
The Decepticons' tampering on the island creates openings to other times, allowing all sorts of things from various times to arrive in the present. The Autobots race to reverse this before it's too late and to stop the Decepticon plot. But in the end, their best hope may be the Dinobots.
#25 - The Rebirth (1) 8.00
Season 4 - Episode 1
The Decepticons get the Plasma Energy Chamber key after an attack on Autobot City. A group of Autobots manage to get the key back after Scourge opens the chamber, but it's energy accidentally sends them to Nebulos, a world locked in civil war between the evil Hive (controlled by Lord Zarak) and rebels that despise machines. The Decepticons pursue the Autobots there and they all get involved in the war.