I can't choose between Jungle and City Hunter. There are parts of other Pred designs I dig, but Winston somehow really captured the essence of the creature and none of the others quite match up overall in quality and design to those originals.
I dig Wolf and Berserker big time too as honorable mentions, but the original two, particularly mask-less, still look better. The AvP Preds always irked me, way too bulky, they lose the essence of the originsl hunter look and obviously mask less, Scsr looked EPICLY awful. The only thing I really like about AvP appearance wise is Scsrs mask but only because it resembles Anytime.
The first two just own. Doubt they'll ever be topped, though Wolf comes close to being in that category too