I have a box full of headlights.
The hp10 is my favorite. But it depends on what you need one for. I adventure race, so I actually use the light's capabilities. If you just need one for tasks, the hp10 is almost too bright. Up close it reflects enough to blind you. The diffuser helps.
I had a princeton tec apex. It was a nice light but the plastic fell apart. ( a common problem if you do the research on them.) Took them about 4 months to replace it. Same story with the replacement...bad plastic. It just eventually disintegrated. I've had a couple other princeton tec lights that the plastic cracked on..the arora, I think. They make great lights, as far as user interface and brightness, but if they won't hold together, I'm done with them.
The only PT light I've had that hasn't broken is the EOS. It's a nice light but the battery life isn't as good as some others. If you don't need a super bright light, don't mind less than optimum battery life, they are simple and seem to be durable.
I wish I'd seen the above zebra site before I bought one from the 4sevens site. The above site has them cheaper. They are a really great light for a task light. Beautiful flood beam with no shadows. It's like standing in sunlight. They're simple and rugged, built from aluminum. Good battery life. I keep one hanging around my neck, and they light the path, while the hp10 on my head is a directional spot beam.
I've a petzl myo3 or 5, can't remember. It's a good light. Well built and rugged. Bright enough with decent battery life. The user interface is a bit more crude (twist bezel) but simple is good as far as I'm concerned.
I've a couple black diamond lights. The icon ( pretty chincy feeling. very mediocre) and one of their most powerful (four batteries, incandescent/led) I forget the name. It was mediocre too. Battery hog without being that bright, cheap feeling.
My recomendations: Go for the hp10 if you really want to see anything and everything at night like you've got a car headlight strapped to your forehead. Get one of the zebra AA lights if you want a work/task light. Go for the EOS if you're really budget concious and don't need the best.
ETA: I don't know any backpackers who tote a 4AA light. They just aren't really worth the weight, for that task. Even the EOS is heavy for backpacking. I take my zebra when I hit the trails.