The original Classics version was nice for it's creativity and real world jet mode paint scheme. But his face wasn't painted, his red was a bit on the orange side, and his gray a bit blue.
Henkei was up next and got pretty much everything right. Great gray color, painted face, nice red, light blue parts, and extra detailing. The only negative to me is the chrome (I like chrome, just not on the launchers).
Universe is a poor man's Henkei in my opinion. It uses the same paint masks but eliminates a good portion of them. Coupled withe the off white, overly bright red, and dark blue - it just doesn't work as well. Besides the face, I still prefer the Classics version to this one.
Ghost is nice if you like that. The clear purple plastic is cool.
Now we have the Classics Seeker set version coming up as well, which is the most cartoon accurate of them all. The only thing it doesn't have right are the knees. It's very similar to the Henkei just with less white detailing and some other changes here and there.