In the old days, the foam had to fit your noggin to feel comfy. Today, with adjustable band tensioning the choices are much wider. All the Bell helmets and now-Bell-owned Giros are great, and you will probably feel comfy, fit-wise, so then you make decisions based on ventilation--you want max for hot weather, not for cold weather. There's nothing wrong with having two helmets, e.g. I love my Bell Variant most of the time, but the Ionos (white heat reflective and max-vents) takes the mid-summer gold medal. The Ionos comes with a skullcap for cooler days, actually. But it doesn't have Windstopper, which if it did, would be wowzma.

Other brands are fine too. This isn't rocket science, although maybe it should be, to protect your brain (if yours is worth protecting and reproducing).