If you want to see a film that revels in just being a big fun, cheesy, actionfest then you can do far worse than going to see Transformers. I went to see it at the weekend and really enjoyed the whole thing. The movie kind of feels like two different films with a definite change when the Transformers start talking. The Transformers (at least the Autobots), when first introduced, seem to be aimed at children (which is fair enough as they are childrens toys) which is slightly out of place from the lead up that's been given, but you deal with it by the general coolness of the CGI. There was a completely superfluous subplot with the NSA signal analysts, which could easily have been cut without really affecting the films overall plot, but it was harmless enough having it in there. Some of the battle scenes between the Autobots and Decepticons are pretty hard to follow as they're really fast paced with so much going on. They definitely require being watched on a huge cinema screen. I was surprised that there was a quite a large comedy element to the film, which actually worked really well. You'll be unsurprised that like with most recent blockbusters they've set themselves up for the sequel, but I'll be looking forward to it - maybe they'll even get Leonard Nimoy back as a Transformer (it might be pushing it to have Orson Welles again though).
As you'd expect you've got to suspend the thinking part of your brain for the film, but in general I sat through the film with a big smile on my face thinking "Woah, that's cool".