I disagree with the "bigger is better" option here. I have owned a bunch of lights from the small front blinkies to the 1200 lumen things The Golden Boy suggests. If you are in oncoming traffic, particularly bike traffic, like a MUP or crossing a bridge (common in NYC), then the super bright lights blind the riders coming toward you.

Better optics, rather than more power, make better lights.

For my bicycles without dynamos, I prefer lights that use batteries. The reason for this is that you can get batteries *anywhere*. If your charge goes out on a rechargeable light, you are out of luck.

I have a Planet Bike Blaze 2 Watt Micro that is my preferred light. It throws 139 Lumens, and is plenty bright for much of the riding I do. I also have a Serfas SL-255 that I have on the handlebars if I need more. The mount on the PB light is great. The Serfas one is not as good because it is not as stable.

I use the Eneloop rechargeable batteries and have a recharger at home.