Ummmm the Hot ones
Sorry but that's a very broad question. What kind of sauces do you like? Sweet/Tangy/ Fruity/etc. There are some real winners here.
Although I haven't personally tried them yet, I hear nothing but good things about Lucky Dog Hot Sauce and Pex and about 100 more I can't remember right now. Unless you're allergic to capsaicin you gonna find you like them all.