Electron's self-contained light is relatively low on power but high on practical value.
The Terra 3 is heavily influenced by Exposure's MaxX-D but has half the power at under half the price. The plastic thumbwheel-secured clamp is permanently fixed so it won't work as a head lamp. It works fine on the bars though, and removes battery bag-homing hassle.
The single power button gives run-time feedback on the generous battery time, which is managed through four power levels.
Despite low max power the relatively focused beam gives more than enough reach and clarity for most situations and there's no distracting halos or dark spots. It's best teamed with a helmet light for twistier more technical trails, but it's still well priced and very reliable.