I'm quite the chilehead. In addition to pouring hot sauce on pretty much anything where it makes sense, I even grow my own peppers in pots on the patio. They do really well in this arrangement, and I get lots of pods every year. Way more than I can use at one time, in fact, but freezing works really well. I've still got some ghosts from two years ago in my freezer.
I actually cut up a home-grown ghost pepper and sprinkled it on top of some frozen burritos once--there's an experience I will not repeat. I was trying to find my limit and I found it. On the other hand, a stir fry made with a chopped ghost pepper is blistering but still tolerable (for me at least), and I've made it on many occasions. Funny how nobody else is brave enough to eat a bowl.
I find that the super chili, habanero, and jalapeno are some of the most versatile. Each has a unique flavor, and of course they're all different heat levels. I use these for pretty much anything I want to spice up. In addition, Thai chilis make wonderful stir frys (particularly if you're serving people who can't handle habaneros or ghosts), Tabascos spice up ramen noodles nicely, and serranos work well for my flame grilled fajitas. Poblanos, while not particularly hot, make an excellent alternative to your standard sweet bell pepper if you want a bit of kick, as does the cajun belle, which offers a rare combination of sweet and spicy.