The Bhut Jolokia, or "ghost pepper" was, for a time, the hottest pepper on the planet, as certified by the Guinness Book of World Records. It is definitely hotter than Tabasco sauce. One thousand people in Copenhagen downed one simultaneously as part of a spicy stunt put on by pepper enthusiast Claus Pilgaard. There were tears.
A pepper's heat is measured in Scoville heat units (SHU), and the ghost pepper apparently has a one million SHU rating—jalapenos meanwhile, score around 2,500–8,000 SHU. They're hot. And it appears to be a delayed heat. The brave among you can buy some.