I personally just bought a Niterider Lumina 650, so far no complaints. I have been using it for about 3 weeks now of commuting here around the Seattle area. Been through some good rain and no issues. It throws out a lot of light, I usually leave it on medium if is dark, otherwise flash for the daylight.

I know it is more expensive than those chinese knock offs, but I don't think the QA is there (just an opinion, no basis)