I recently ordered the new Ixon IQ Premium bike light. If you're familiar with dynamo lights, Busch and Mueller came out with a new Lumotec Premium dynamo light this year, the Ixon IQ Premium is it's battery equivalent.
What's interesting about their lights is that they use a highly shaped beam with a distinct cutoff, just like a car headlight. It's beam pattern also varies in brightness across the beam to give you an evenly-bright beam when it hits the road and not having a hotspot like most round-beam lights do. While people sometimes talk about not wasting light into the trees, the biggest advantage is that my eyes always adjust to the brightest source of light - when that's a hotspot from the light I cannot see around me nearly as well and I end up with tunnel vision, seeing mostly only what the light illuminates directly. With the Ixon IQ there's no hotspot. I could ramble on, but so far, it's pretty amazing.
Here are some pics I took of the light on the bike. In real life, it's not quite this bright, but the even lower exposure pics I took were to dim so I went with this one. This was the best I could do hand-holding the camera, it's a little blurry, and for some reason the camera angle makes the street look shorter than it is, but it gets you the idea -
Here the picture is not blurry, but the bike (and thus the light) are tilted to the side a bit because I put down the kickstand. That's why it appears shorter on the left than on the right -
Here's a pic I tried to take of my Lumotec Cyo - the dynamo version that's the predessor to the current "premium" version from above. Since I had to be pedalling and moving to get full brightness, it's pretty blurry, but you get the idea - the Cyo covers a decent amount of the street, but the new Premium version really covers more -
P.S. Wanted to add some info from what I found.
1. If you order the version of the light without batteries, it also does not come with the plug-into-the-light charger. So if you want to order your own batteries separately (which I did), you'll also have to order the charger. Or, of course, use your own external charger to charge the AA batteries.
2. The mount the light comes with does not appear to fit your average bike handlebars. Apparently it's adjust for "standard" bars or something, but almost all american bikes are "oversized" bars.
You don't actually need to order a second mount (which I did, they listed an "oversized" mount so I thought I needed a second mount). You need to take the light off the mount, underneath the light there's a screw. Unscrew the screw, then you can open up the mount. Inside you change where the mount-strap is connected to the outermost point. Put everything back together, and now it fits on a regular "oversized" handlebar.
EDIT: People pointed out the Phillips Saferide, I ordered one from Amazon and tried it out, but it turns out it wasn't the latest version so I'm returning it and ordering the latest version from Europe. Comparing the two that I have though, short version is that I think it's a tie between the Saferide and the Ixon IQ.
The Phillips Saferide is like riding behind a wall of light, it lights up what it hits very well, but you can't see as well outside of the beam area. It's biggest drawback is battery life - sounds like it's 1.5 hours on high, then additional time on low after that. I've order the v2 one from Europe and I'm going to test it when it gets here.
The Ixon IQ I'd characterize more as like magically lighting up the road without realizing you have a light on. It doesn't bring out the road details as much but it does a decent job at it (good enough for me), it's beam is a little wider and it lets you see outside the beam better. It also has much, much better batter life at 4-5 hours on high. You can see my other thoughts on it here -
Ixon IQ Premium Bike Light may be the best Bike Light I've ever seen (Lumotec Cyo Pr)
EDIT 2: A number of people who have used the light seem to have found it to dim as a light. The Saferide is a brighter light that lights up the ground brighter and more clearly. I have found myself with a preference for the Saferide as it puts out a nicer light that also is better at overcoming things like oncoming headlights...unfortunately the saferide. Sigh.