I'm not particularly fond of any of them. It would be easier to evaluate which is the worst, since most of them have been spectacularly bad. :P Here's a great example of how. But if I had to choose which one I disliked least? ...it's probably a toss-up between 1990 and 2007. Knowing for sure would involve watching them again, and I don't plan to do that immediately. XD That said, I haven't seen the 2014 film (which all my friends loathe), and I haven't seen Turtles Forever (which most of my friends love). I abstain.