I like a lot of different hot sauces. I tend to either love or hate a hot sauce. I prefer something with flavor, not just heat. Underrated, in my opinion, is TraderJoe's hot sauces (habenero (very hot) and jalapeno (tabascoish, but not as thin)). I also like the frequently mentioned Cholula and El Yucateco which they have at my local mediocre Mexican joint.
The key for me is to have different sauces for different cuisine. I love Sriracha on Asian inspired dishes and grilled meat, but not Mexican. Similarly, I love a smokey (chipotle, or I have a chocolate habanero that is like hot mole), but not on Asian foods. I think mustard-based hot sauces have more potential than has been developed.