It's not actually that nice. Guantánamo used/uses heavy metal played at high volume, continually, in a small space, as a form of torture. Imagine being forced to sit next to the speakers at a disco for 24h... urk. Not fatal either, though I imagine being tortured to the strains of "Smoke on the Water" must do terrible things to the sanity. The torturers would have to block their ears, of course. Forced positions are similarly unpleasant (e.g. vertical but without being able to sit, stand or even slump).
The best (worst) tortures are the ones that target the mind. Since they're aiming to kill him, they'll be going for the body, too — but in a subtler way. Unpredictability is a powerful weapon. Bodily damage isn't essential; mental torture is (supposedly) a lot harder to deal with.
Then, of course, your torturers are aiming to kill him, and probably with a more personal approach... <ham>TO THE PAIN!</ham> Again, it's what it does to the mind rather than the body that's the key here. Disassemble the MC: break his fingers, joint by joint; tear out the nails (after the fingers have been broken); break his eardrums; break his jaw (especially if he relies on words to defend himself); dislocation of various joints. Or you can get more creative, though this can verge on Narm for reader and prisoner. Force an instrument down his throat to make him vomit. Force his mouth full of objects so that not only is his jaw stretched to breaking point but he can barely breathe. Veeeery slowly scrape away at his skin, eventually removing the top layers (believe me, it hurts like HELL). Weights on the chest to crush but not kill (yet). Or go Aztec: open the chest and squeeze the heart. Careful disembowelment has always been popular.
If you want to combine humiliation with body horror, then go for the groin. We're also very protective of our mouths and lips (as they're extremely sensitive). Threatening the eyes is good for fear, but it's pretty hard to be subtle there, since they're so delicate. An attack to the spine is terrifying, because physically we have almost no defences against it: place the head in a position that might
break the neck but won't allow the prisoner to do it (escape by suicide foiled mwahaha).
Er... I just realised what a long post that was. I'm not that depraved, I swear. I'm just very bad at brevity.
edited 11th Jun '11 6:53:46 PM by LongLiveHumour