I'll agree with the Serfas Shield being a good light, but I have two caveats - the clip mount is HOPELESS - I put it on the belt on my seat wedge pack and it fell off the very first day after just a few miles of riding - the clip is too smooth and just falls off very easily.

Also, mine had water inside it after two days of riding in light rain (with the USB cap on properly). I sent a photo to Serfas and they immediately offered to replace it, so I assume it's not common, but we'll see after I get the replacement back and take it out in the wet a few more times.