The hot ticket for one who regularly commutes after dark is a hub dynamo. It requires some initial investment, as you must have your front wheel rebuilt with the new hub, but a hub dynamo is very efficient when compared to a tire-driven dynamo. There's less pedal effort required, it's quiet, and the lights don't go out when the tires get wet (tire driven dynamos tend to slip when the sidewall gets wet.) And forget about batteries and chargers etc.

There are lights specifically made for use with dynamos, with a capacitor built in, which will remain on for a time after motion has stopped, so your lights don't go out when you stop at an intersection.

The downside is that you carry the weight of the dynamo and lights with you all the time.
The benefit is that you have the dynamo and lights with you all the time.

There's a lot of info here:
http://www.peterwhitecycles.com/Schmidt-Lumotec.asp

Also, do a search for hub dynamo and you will uncover a wealth of information and opinion.