Agreed the head is bassicly a plum bob.

Chest Pecs Ankles Knees

glutes

chest/lumbar. though subtly, they can often change the outcome of a match completely.

subtly?
they effect everything, especially the chest >.>

Imo, chest and wrists. Wrists are really useful sometimes, to break off your enemy.

elbows and knees
lol...
if we keep on going like this well all just state every joint and that defeats the purpose of this thread which doesnt make much sense anyway

For me, every joint is same important.

I can see suo's point about wrists. My currently favorite Sambo tactic is to go for a headgrab, then releasing the next turn and just dragging my extended wrist against my opponent, breaking their neck.

But I can't think of a single move that I use that doesn't use almost all of the joints. Even my Joust opener forces or relaxes everything but my elbows, and for that matter I say none of them.

i would say all your middle joints
chest lumbar abs and glutes as i use them the most