Personally, my favorites are:

1.) Warrington Gillette's version of Jason unmasked in part 2.

2.) Ted White's version in part 4

3.) Derek Mear's version in the remake (Which was inspired by the looks of Jason in part 2 and part 4)

While I prefer Jason with hair, I don't prefer him with too much hair, as seen in part 2 and he just doesn't have enough hair in part 4 to make him look creepy, but the remake offers to compensate for that by making him partially bald and having partially hair, which would make my ultimate favorite look that of Derek Mears'.

My favourite unmasked Jason would have to be in Part 3- I love it when he lifts his mask to show Chris his face after the 'hanging' that always creeped me out. Also think the scene in Chris's dream at the end, when she can see Jason in the top window of the house, is really freaky too.

While my favorite Jason is Ted White, I like the look of Jason unmasked in Part 2. The reason being I see Ted White's Jason as what Jason should look like with the Mask on, but mask off I thought it was too corpse looking.

Yeah Ted's Jason looks great with the mask on but I have never been a fan of Jason's face in TFC. For starters, like you mention Bradp56, his face did look a bit 'corpse-ish' (for lack of a better word) once the mask came off- now I dunno if it was due to the lighting or not but he looked very dark. I also always thought his bottom jaw was a little overdone and looked a little fake, but thats just me.

Thats about the only issue I have with TFC, and I dont see these things as negatives- its still the best installment.

The Final Chapter. We now get to see what that charming little boy in the lake looks like grown up. And after massive injuries, especially to the face. It's so creepy, yet still believable. Gillette's makeup takes second, since he also completely took us by surprise, and the look was just as shocking.

I agree RangerMatt, his face is dark and looks little to miscolored. Almost like a dark grey.

<<<---------- The image on the left is truly Jason personified, but that's just my opinion!

What I consider the "classic" Friday the 13ths is parts 1-5. In all these movies, the killer was shrouded to some degree throughout the first half of the movie (even when masked). The unmasking would come as a surprise to the viewer, and like mentioned above, would be for shock value. Gillette's unmasking was one of the best executed; we can only imagine what he turned into, and they cleverly hid his face from the audience once Ginny pulled off his mask. Then, in what's probably the most unexpected jump scares on the series, Jason comes back, machete and all, his deformed face clear as daylight.
Some of the other ones went a little far, though. Showing too much kinda loses the effect, like in Part 4 and 7. Though, Part 4 is justified, because it's fitting that the last thing we'd see of Jason is the face that scared us to death in the first movie. I don't hold it against FvJ or JGTH for not showing his face. We're left to wonder what's under there, and from his appearances, it ain't pretty.

By the way, even though Jason's not officially a zombie in The Final Chapter, the "corpse" look is definately intentional. He lost so much blood the previous days that that's a realistic idea of how he'd look.