My idea...
TF2 starts about 2 years later. Sam and Mikaela are both in college and still together. With Bumblebee as his car. Many of the college kids are jealous of Sam and he has become popular because of his cool looking car. This goes to his head and he becomes ignorant towards Mikaela causing problems.
Meanwhile Optimus has created a refuge in the Rocky Mountains for all Autobots. The base he has created runs off the power of the scrap of the All Spark he has... (the piece he picks up at the end of TF)
This has energy but not much so he has Ironhide and co looking out for new resource they stumble upon small crystals of energon in the ground. This energon was created when the TF's crashed on earth when they crashed something triggered various substances in the earth to create energon.
Oh and about 4 new TF's have arrived. Wheeljack, Tracks, Afterburner and Hot Rod.
Meanwhile strange events have been happening Laurentian Abyss...
Starscream like Optimus has sent out a message to all Decepticons out there that "Megatron is dead and the Humans are responsible Earth is a new enemy meet me on the 4th planet"
Starscream lands on Mars where he awaits his brothers.
Sector seven have resurfaced and are using TF technology to fish out Megatron and co. from the Laurentian Abyss. They succeed and Megatron awakens wanting revenge but he is weak and the head of S7 Tom Banachekmakes a deal with him... he knows how to get to Prime if Megatron lets S7 be his earth "spies".
Megatron agrees and goes into hiding as a tank. He feels unusual and then he realizes the all spark is taking him over like a virus making him stronger rebuilding him internally into Galvatron.
Meanwhile Sam and Mikaela break up because Sam has changed he's become a jerk. Sam doesn't care he's popular with more girls then he can imagine...
while Mikaela storms off she is kidnapped by S7.
Sam cannot find her and he and bumblebee travel to the Rockies telling his parents he is off on a trip with friends..
Optimus is glad bumblebee has arrived just in time to see if energon works as a power source.. Sam tells him that Mikaela is missing and Optimus tells Sam he cannot help. Sam storms off bumblebee follows.
On Mars Starscream lies and tells the rest of the Decepticons that Megatron made him incharge and he says they must destroy earth.. so the Decepticons head for earth (about 8 don't know which... they travel on Astrotrain to the moon which they plan on destroying)
Starscream wants to kill Optimus so he sends a message saying they are going to destroy the moon and wipeout humanity etc... Galvatron picks up on this message and heads off to the moon with the Autobots not far behind.
Que big space battle.
Starscream is tossed to earth by Galvatron leaving Prime and co to fight the rest who eventually land on earth.
S7 call in on Galvatron saying they have Mikaela.. Galvatron says that he must leave for business elsewhere...
Bumblebee is asked to help out Prime but Sam begs him to stay so he does..
Something here leads them to Galvatron and S7 with Mikaela..
Sam faces Galvatron crapping himself but to get Mikaela back because its his fault etc..
Galvatron is about to crush Sam when Bumblebee transforms and saves him.. bumblebee sends out a message to prime..
Sam and Mikaela run off while fighting a bunch of S7..
Bumblebee gets owned.. Prime is just in time to see the final blow... and charges at Galvatron...
the rest of the Autobots arrive followed by the Decepticons.. the battle is even and Decepticons retreat saying we will be back blah blah blah..
Sam and Mikaela get back together.. Bumblebee is rebuilt into Goldbug.
Then the bases comp tracks something huge incoming to earth.. Galvatron also hidden on earth receives this... they know who it is.... Cliffhanger..
Pretty crap i know but i was bored lol..
So please don't be telling me it's crap because i know it is lol