If you have 2 and half hours and really enjoy large robots beating the crap out of each other then Transformers 2 is for you. It's basically 180 minutes of CGI and Shia Labeouf looking annoyed and shouting a lot.
If, however, you were actually expecting a film (i.e. plot, story, character development, themes, direction, acting) then I would save your money. You won't find any of that here.