Caribbean - Scotch Bonnet is much like a Habanero both are very nice
South American - Aji Amarillo is awesome - My favorite right up next to Chocolate Habanero - Their flavors are very different but love them both.
American - Fresnos deserve a honorable mention, one of my first peppers to grow on my quest for the next great one. But I have to say Numex Big Jim not only for it's massive size
but range of flavors from green to red.
Look for these not all are hot
And a member on this thread suggested