Others have already suggested the Cree XML T6 lights that I use and recommend for front lights. I'll add that they cost less and are far brighter than the Knog lights. Knog lights are cute but that's all they have going for them. The Crees are real lights in that you can see the road by them. "Be seen" lights are mostly useless for anything. They really can't "be seen" in most situations and they certainly aren't bright enough to see the road.

Most people make the mistake of thinking that you don't need much light in an urban environment because there is a lot of ambient light. However your light is going to have to compete with all those ambient light sources. You really need more light in a city then you do out in the country.