Headlight: Nite Rider Trail Rat. Great light, not cheap (but not as high as they come!)

Taillight: Cateye T-1000. Very bright and flashy.

Also reflective ankle thingies, extra blinkies on my panniers, and reflective/hi viz jacket and shirts. I commute through the winter, but avoid night riding as much as possible because of my vision problems. My evening winter commutes are 1 mile to the Metro near my office on a lit street, and two miles from the Metro to my house on well-lit residential streets, but it's still important to be as visible as possible. But the morning commute remains 14 miles because it's light, at least most of the way.