I'm partial to the Black Diamond Sprinter (lists for $79, but can be found on Amazon.com for closer to $60). It has a good balance for me of brightness and burn time, and it has a flashing red LED built into the back for added visibility on the street. The main drawback is the price. Others have recommended the Petzl Tikka line, which comes more affordably.
Here's a nice blog post comparing various Black Diamond headlamps:
I have two headlamps, a Petzl and a Black Diamond. Both are amply bright and have survived rain. Scour the internet and you can find good headlamps in the $30 price range (steepandcheap.com is a good source if you don't mind waiting for a headlamp to show up for sale).
However, I seldom wear them when running on familiar roads and trails. Only once has it been so dark that I couldn't see where I was running.