Just to update, I now think of the movies in the following order (from best to worst):

1: Transformers: Magical - live action bots on the big screen finally!
2: Age of Extinction: Much more robot character dialogue and development (for at least some of the characters) and a big-ass Grimlock to boot!
3: Dark of the Moon: Long but good
4: Revenge of the Fallen: Eh, at least Ravage looked kinda cool