I use a Zebralight SC600 flashlight. It's brightest continuous setting is 500 lumens, it has great run time on an 18650 battery, and is small and lightweight. Flashlights work for me as it is easy to carry extra batteries so I never have to worry about running out of power.

Took a night ride tonight and it was more than enough, even on the lower settings (330 lumens) there was plenty of light.

Keep in mind it isn't all about lumens, beam pattern and bin tint can make a lower lumens rated light a better choice. I prefer neutral tints, in the flashlight world this info is readily available, cruising the websites of bike light manufacturers I see they don't tell you what LED tint they use, not good IMHO as a crappy tint can make a great light useless.