I have a weak spot for hot sauces...I've got between 150 and 200 different ones...
One of the most complex (and not too hot) is Jump Up And Kiss Me. For a nice kick, I like Tapatio Sala Picante or Bufalo Chipotle (from Mexico). Dave's Gourmet Insanity Sauce was quite tasty as well, and I have a bottle of his Total Insanity Sauce, that I still have to try.
I think I'm most proud of my bottle of Da'Bomb Beyond Insanity - I hope to add their Ground Zero to the collection one time: supposed to be the hottest sauce on Earth!
A GREAT hot sauce is made in London: the Cool Chile Co. Habanaro Hot Sauce. I bought some bottles at the Borough Market, but have yet a single one remaining.