There's NO way to write an UNBIASED review for this movie.

Rating: 3/10 (11 July 2009)

I want to do justice for the franchise. So I will now write a non-biased review. But really, I can't see that happening.
So how about this? If you see it as a usual type of movie, of course, Transformers: Revenge of the Fallen is an epic fail. There were no character development. The storyline – I won't even call it rushed – was a mess! So much plot holes that you can shove Optimus Prime in them and back again. There was too many missed opportunity for a better plot such as the "Sam-as-a-fugitive" storyline which could've been more in depth or even "Jetfire, the old Decepticon turned good" deserves a better story than that. And a lot of WTF moments. And one more thing, I remember the filmmaker saying that they had to write in Shia LaBeouf's hand injury -- that was also one of the WTF moments.
But the only way to write a good review for this movie is that you have to see it as a "Michael Bay type" movie. Then this is the best movie ever made. His best effort yet. There were plenty of explosions that your ears could go numb, slow-motion sequences that most probably made up half an hour of the movie, and some more explosions! There are also random Transformers running around that you won't even know who is fighting what.
I don't think anyone is capable of making a better "Michael Bay type" movie than this. Heck, I don't even think Bay himself can top this.