I've used a Fenix LD-20 light for about 5 years. It has been a great light for someone using AA rechargeable batteries, but there are many options that are much less expensive these days. If buying a flashlight now, I would get one that runs on 18650 rechargeables, which are brighter and hold charges longer than AAs.

Oops, just visited that link and realized that the Fenix BT-20 is a dedicated bike light. I didn't realize that Fenix was making them now. All I can say about that is that my Fenix flashlight has been 100% reliable and durable over 5 years of use. I use it as a helmet light while commuting 3-5 days/week year-round.