For cyclists around here, I'd recommend Cygolite lights, they are amazing:
On my bike I use a couple cheap silicone mounts[1] to hold my regular bright LED hand flashlights. I like that the flashlights serve double duty on the bike and that they can be easily removed at my destination.
1. http://www.dx.com/p/universal-bicycle-flashlight-lamp-nylon-...
The Metro 500 comes with an easy to remove clip that allows you to keep the mount on the bike while you get your light safe. Handy, but can break in cold weather due to plastic resistance.
500 lumen is quite enough for my needs.
I have a Fenix BT20 which is a great light but I have been looking for something a bit stronger. The Fenix BT30 is only ~ $100 for 1800 burst lumens.