Currently, the hottest pepper in the world is the Carolina Reaper. To put it in perspective, it's about 1000 times hotter than a jalapeño. One Thousand.
The Carolina Reaper was created by Ed Currie who says: "When you bite into it, the initial taste is sweet. You go, wow, that wasn't so bad. And then immediately, that vast amount of capsaicin takes over and it's kind of like eating molten lava."
Little red, wrinkly, evil demons. Even a habanero doesn't come close.
Have a look at 24Bite to see where your favorite pepper fits into the chile pepper capsaicin scale and check how it compares to the Carolina Reaper.