Douglah
Douglah x Chocolate Scorpion
7 Pot Congo SR Gigantic (this one isn't a terrible pepper per say, but you asked for 3 and this is the only one that I could think of, out of the rest I've eaten, that consistently had an offputting flavor)
1.Orange Habs - blech.....which is weird seeing as I really like choco habs and Caribbean red habs and Bahamian goats.
2. and 3...anything hotter than a scorpion.