I've got 2
Being skinned with a cheese grater until you are on the verge of death, then your wrists and ankles tied together, then tie a brick to your feet and throw you in the ocean

Saltwater + open wound (you've been skinned) for 1 minute (before u die of oxygen deprivation) =
OUCH
or
You have 2litres of water to drink, and if you don't drink it by the end of a certain amount of time you get your throat slit, then tied to a wall, upside down, and a tube on your downstairs area (yeah you guys know what i mean) going into your mouth, then cellotaped to your mouth and down stairs, so there isnt a single gap going from ur .... to your mouth, but you can still breathe in through your mouth... When you have to piss... yeah, u either swallow, ur ur bladder explodes, so potentially you might not die...