The tried and true Black Diamond Express ice screw is a top contender for best ice screw. It has well-designed large teeth that started easily even on the coldest of days. The slightly tapered tube minimizes friction while driving the screw into the ice. It has excellent racking and superb ergonomics.
It has a slightly tapered tube so that the teeth are slightly bigger than the shaft but smaller than the threads. This makes for far less friction while driving it home. This, combined with large sharp teeth, made the Express screw among the easiest to start. This difference was even more evident as the temperature dropped below 15F where the Express narrowly beats the Grivel 360 and Grivel Helix Screw. Once started the large color-coded crank knob helps to quickly drive the screw home. The crank knob has a slight flare that makes it easier to grab with gloves and takes a slight bite out of the arm pump. The hanger has more play than some ice screws we tested but didn't have near the clearance of the Grivel 360. The Express is one of the better racking screws and most people will put 5-7 screws on each ice clipper. Another thing we liked about the hanger is you can clip two carabiners into it, a nice plus for belays, especially if you ever climb with three people.
It's hardly a huge flaw but some screws like the Grivel 360 performed far better in more featured or chandler type ice features. Our only other slight downside to the Express is that the teeth don't seem to hold up as well as those on other screws we tested. When we occasionally ran them too deep into rock while attempting to place them in ice that was too thin, they dulled slightly faster than those on the Grivel 360 or Helix. But they were slightly more durable than those on the DMM Revolution.
The Black Diamond Express screw is at home everywhere water is frozen solid. Great for waterfall ice climbing, alpine climbing and general mountaineering.