I've been using the Niteflux RedZone 8 as a rear light for around two months now.

These are self contained USB chargeable 8W dual bulb lights. They are pretty powerful and don't need to be directed in any direction. They also seem to be quite well made ans so far I've had no problems with them.

The website is here:

http://niteflux.com/

As a front light I've been using a much cheaper 4 LED solar rechargeable light. The light works quite well but of late has started to act up on me. Perhaps the internal electronics isn't so great. I'm considering changing to pre-ordering the White Zone 8. But you should decide if you want to see or be seen when it comes to front lights. For me it's the latter, so the White Zone should be alright.