The benchmark compact front light, 6V 2.4W, runtime about 3h20, weight with mount 210g
The newer model, MC-200, has a very similar beam
Not really wide enough for sustained night riding, but two Micros works well for some people.
The same light as above, but fitted with lithium batteries
Runtime about 4h30, weight with mount 170g
Unfortunately these lithiums were already about 2h30 old - so the difference is not really very marked here - even so you can see the wider beam, and less patterning.
The Lumotec and Cateye Micro beams are very similar - the poor showing here is because the Lumotec has a genuine 6V bulb, which performs best when slightly overvolted, as would happen when driven from a dynamo.
In this picture, by contrast, it is undervolted due to being run off 4xAA cells.
For a better view of this light, see the Beam Comparison page by Andreas Oehler / Olaf Schultz
This light is an old favourite of mine, 3V 2W, runtime about 5h30, weight 230g.
This is a focussable beam, set here to about the mid-way point, which gives better width than the Micro.
Cannot compete for brightness, though.
Another old favourite, again a focussable light, 4.5V 1W, non-halogen bulb,
this lamp will run for 2 nights using its usual 'flat 4.5V' (MN1203) battery pack.
The brightest cycle led light so far, 220g, runs about 18h
although it will run much longer than that, as you see even with nearly new batteries there is very little width, so there is not much point in running it as a 'visibility' light.
See LEDs comparison for more LED lights