Magicshine, or a P7 flashlight. I actually have both on my bike. I use the MagicShine primarily, the P7 is for backup. However, if I were doing it again, I'd personally go for two P7s - I think you should have a backup light, and you can get all that for < $100. I had some trouble with my MTE 5 mode P7 - it's still what I'd buy though. In my case, the endcap switch just got loose, it started cutting out on a ride, I tightened the switch when I got home, no trouble since.

The downside to the flashlight is runtime - about an hour. The upside is, totally self contained, goes on and off the bike in 5 seconds, totally waterproof, no wires or connectors to wear out.