I run a 250 lumen NiteRider rechargeable on front and a rechargeable NiteRider Solas on back. When it comes to being seen, and not getting hit, this is no time to go cheap.

+1

I also run NR Lumina up front (a 650 in my case), and a (sometimes two) Solas in the back. I recently supplemented these with a Dinotte XML-3 on my helmet (mainly because the majority of my commute is on unlit streets and MUP, but also to have redundancy) and a Dinotte 300 in back - that 300 is way brighter than the Solas (which I always thought was plenty bright).