The hottest edible thing in the world that I know of would be the Chocolate Habalokia: c800,000 SHU which is A cross between a Chocolate Habanero and a Ghost Chilli pepper.
I'm not sure of anything else that is hotter than that pepper that would be edible but I'm sure there has to be something else even hotter but it may not be edible to us humans.
Another pretty darn hot pepper is Peach Ghost Scorpion: 750,000+ Scoville heat units A cross between a Ghost Chilli (Bhut jolokia) and a Trinidad Scorpion.
And then the Carolina Reaper which is another pretty darn hot pepper but most people are unable to finish either of those peppers I listed above.