KSC75 are usually very comfortable, sometimes they can pinch. IIRC my Denon D1001s were super comfortable, but I don't own them anymore. One of my first pairs of headphones was the Sennheiser 435, probably the most comfortable but the sound isn't any better than $10 KSC75s.
My latest headphone purchase let me down in the comfort department, HD 555s. My head is huge though and I have jaw problems so the sides of my face usually hurt whether or not I'm wearing headphones. I should have done a little more research though, it seems AD 700s are the headphones that favor big heads so that will be my next purchase.