Alpkit Gamma
Petzel Myo Xp
fenix HP10

will be used for fell running?

The alpkit beats the Pezel hands down and is half the price.

The alpkit is bright enough but does noticeably dim when the batteries start giving way. The red light on the back of the alpkit battery pack is useful for the road stretch home.

If you have the money for it and take running seriously enough you may want to consider an ayup head unit on a head strap with the small 3 hr battery.

that fenix is pretty expensive from the UK. maybe something from deal extreme might work – whatever you do, Id get one with the battery pack on the back of the head band – most DX ones have the battery on the back of the lamp.
http://www.dealextreme.com/products.dx/category.906

Alpkit is superb for the money. Miles better than a Petzl I've got that cost 3 times as much – I think they may have improved the LEDs now on the Petzl but I'm not sure.

The latest Petzls have brighter LEDs, have a look at the latest version Petzl Tikka XP which has a useful diffuser on the main beam, so you can get more of a spread than a spot if you want to.

The Alpkit Gamma is great value for money and does work well, easy to switch on by mistake in your pack though, but if you're on a budget, it's very impressive and the red LED on the back of the battery box is a neat feature.

I've got a myo XP and its **** bright, I run at night in the mountains with zero street light and it lights up the whole trail.

The fenix looks pretty good though, if a bit bulky, the myo xp is pretty compact.

Check out black diamond as well as silva

http://www.buachaille.com/c3-31-0-0-0-1/Head-Torches/

I also run with the flashing mode its plenty bright enough and the battery lasts for ever

Have you considered Hope adventure range.

Alpkit is very good for running, but the beam is a bit too much of a spot at times. Not a major problem, but can limit your speed on tricky descents. I think I'm going to try and make a diffuser for the bottom of the lense on mine, just to spread the light out across the floor a little.

In its favour, it has a green LED, which meany you can read a map at night without losing your night vision and, unlike the usual trick of using red light to read by, you can still see contour lines.