Best helmet for commuting

Skater helmet - name name says it.

Get the Boardman.

The Boardman's a nice lid, and I bought one recently but returned it a couple of days later because the Giro at a similar price point was more comfortable (and more familiar, being pretty much a direct replacement for my last two) and the B' didn't really offer anything extra. Also, a road or hybrid helmet will likely have a level of adjustment for better fit not usually offered in a skate helmet. If you're vain, you'll look like a pillock riding a road bike in that urban lid, equally the Boardman on a BMX.

Why limit it to just the two? Take other things into account, such as colour - you'd be amazed at how much a bright helmet can stand out especially if you filter a bit, and the above mentioned Giro has reflective strips built in which will help with night riding. Several models also have built in lights, or places to put them and the same for cameras. I'm also going to assume that at least at some point the sun shines when you're riding, so do your sunnies fit underneath?

Overall though, and the absolute be all and end all is that no matter what you choose, if it doesn't fit properly it won't be able to do its job. Almost equally, comfort will less likely provide a distraction leading to you making a bad decision on the road.