I will have to wait until later to discuss why I have this opinion (because it would be a spoiler for most people) but I really didn't care for the last one. It was missing so many ties to the first two, and it was *so* predictable. Brad (Frogboy) pretty much had most of it summed up before the movie ever started. I watched most of the scenes thinking "OK, now the next thing that will happen is..." In my opinion, the second one was the best of the three. I also thought that the very end was cheesy...
We have had many debates in the office about this, and I have looked at it from *many* angles. Though there are some good angles to it, I still think that it really lacked the intensity and power of the first two.