I am possibly getting a Sparks ST6-460NW for night riding. No battery pack, 300 lumens (test in a integrated sphere) and neutral white for better perception and color. It can also use 18650 cells so you can get more than 1 with you for looong trips.
Review here: http://www.light-reviews.com/spark_st6-460nw/
Another great light is Zebralights, check them out too. I know these are headlamps, but they are also great for riding at night.