Hahaha, I loved him. In the movie, Megatron is really battered up after his fight with Optimus Prime and is sprawled on the ground while Starscream laughs and kicks him a few times. It was hilarious.

He then orders a retreat and was just going to leave Megatron there but another Decepticon carried him off. Then while they're in space, Starscream decides they need to "lighten the load" of their spaceship so he dumps Megatron out into space and declares himself the new leader.

Then finally during his coronation to be their new leader a repaired/upgraded Megatron shows up and kills him. That was a sad moment.