if you want the best value and brightest light you can get for your bike for under £50, then you want one of these!!!
UltraFire WF-501B SSC-P7 Front Cycle Light - 900 Lumens
Ebay Item number: 140522712300
We all use these lights and the beam is bloody amazing! Like 6000 HID Xenons on a car!! Plus running full beam easily gives 4 hours run time on a full charge plus the light comes with 2 rechargeable batteries and the charger!!
though the handlebar bracket that comes with it is rubbish so get one of these:
Bike Cycle Light Front Torch Mount Bracket Clamp Holder
Ebay Item number: 220767268606
As these hold the torch 100% secure, i even rode Glentress red route and Mabie red route on it no bother, light didn't wobble about or anything.
Also the torch is 100% waterproof too, as i've been out all winter in 80mph storms/ -15degrees ice and snow and the torch never let up once!