Which is the best rechargeable front light in the UK for bikes?

+1 for the Exposure Joystick. Mine is now in its fourth winter of daily commuting, and just works. There are cheaper bang-for-buck options out there, but they are not as neat or durable. 3 hour run time on high (the setting I use) is enough so that if I forget to charge it one day, it still has plenty of life for my one hour commute. Lifetime warranty too.

The RSP Asteri 3w is a great front light:

http://road.cc/content/review/15798-rsp-asteri-3-led-front-light

good beam, well made, runs for absolutely ages.

Also available with a One23 badge on:

http://road.cc/content/review/28727-one23-mega-bright-3

Hope Vision 1 £60-80 pretty ubiquitous, its got 4 steady beam intensity settings and a flashing mode. It comes with bar & helmet mount, tho it might be a bit too bulky up top, runs on 4 x AA's so recharge & replacement is cheap, quick easy. I ride a mixed route that includes completely unlit country park and very dark rural roads & I barely ever have it up to full power.

Bought a Hawking 900 Lumen and its brilliant and better than many more expensive lights and if you look you can get one for £84.99

The Nukelight is good. I've fitted one on my Kalkhoff Pro Connect S, which already comes with a decent B&M headlight. It's great on the road, but really comes into its own when riding through the unlit Richmond and Bushy Parks near our shop.

It's USB recharhable, very light but robust. The most important thing though is how the LED is focused by a series of six lenses into an intensely focused beam. It appears to outshine the beamfield of some car headlights. Extraordinary really, and less than £50 including delivery. Only ever available in limited numbers though.

Nukelight USB rechargable cycle headlight and general purpose torch

The Joystick makes a great helmet light. I use a Toro Mk2 on the bars which is brighter and has a better spread but costs £100 more.
The mount for the Joystick is a simple push in pull out bracket (see their website for a picture) which means that if you knock or catch the light on something it will come off - use the lanyard! I lost one of these in the sea. Had to wait for low tide to retrieve it.
The Toro has a robust metal bar mount with a spring loaded locking catch.
As has been said, it really depends on what you want to use it for and how much you want to spend. At this price level I think Exposure are pretty good. I have had good service from USE (the manufacturers) in the past and would buy their kit again.

I also use the Joystick. I actually bought it as an MTB back up light, but it's plenty good enough for road use even in it's low 12 hour run setting.

What Paul M said. It all depends on what you mean by good.

I use AyUps myself which I bought cheaply at a time when the exchange rates were in sterling's favour. Exposure lights are popular with night riding friends.

A very open ended question, and one with an answer that depends on your needs and budget. I recently bought a Lumicycle LED4Si Pro52 (I reviewed it at my blog flies&bikes).
Possibly rather expensive at £305, but I don't regret the purchase. Excellent battery life, excellent functionality, and very good at lighting up unlit country lanes.

R

Depends on what you mean by "best" - you can get some pretty amazing things if you are prepared to pay enough.

I'll just describe what I have - Exposure Joystick. It is a rechageable Lithium-Ion battery, single LED light, which I certainly find bright enough for on-road use. It comes with a standard helmet-mount but I gather you can get a handlebar mount as well. You can also get a red LED rear light which will clip to it and feed off its battery (for helmet use).

The light looks much like a small maglite torch, and is useful as a torch if used off the bike. I find it runs for about 1.5 hours before the amber light shows on the on-off button - that means about half-charge, with green light from 100% down to 50% and a red light below 25%.

I am pleased with it, and can recommend it but it is reasonably pricey - about £150 with the standard mount. It is also made in England - Petworth, in Sussex. Exposure also make some more powerful (and more expensive) models.