For me the death of Jill Masterson is still the most upsetting. Covered in gold and allowed to suffocate, creepy and unsettling.
Dying from gold paint sounds a bit too implausible and I haven't heard of any body paint related deaths, even though it's not pleasant and causes chronic health problems (just ask Virginia Hey during her tenure on Farscape
). More plausibly Oddjob murdered poor Jill by strangulation or smothering or neck breaking, then dragged her corpse into the bathroom suite to apply the gold body paint there, then dragged her onto the bed for that iconic corpse pose.