For example
Robes clip?
Fur armors?
Hoods ?
Yngol's helm clips on females.
Actually most of my helmet wearing characters are all female so I might not be able to help here.
Helm of Yngol is guilty of this crime. God that helmet is horrible in terms of it's clipping.
I don't think any of the hoods clip but I know the helm of yngol does clip pretty bad on females (Never seen it on males)
I've never seen mage robes clip like ever (Though other people could have). Unless you have some hair mods, then clipping is almost everywhere.
Most armor and clothes with high collars (http://i.minus.com/iRsltAFj5y1QR.jpg) tend to clip with the long hairstyles.
I've noticed that the blond hair of my Breton clips through black mage hood when he does certain movements, but not when he just walks around. You probably wouldn't even notice this if your character has dark hair though.
Now you aren't planning an elf, but I recall that I stopped using the Dark Brotherhood hood when I saw that my Dunmer's right ear clipped through it. Very annoying since it suited her so well.
..................Hagrid...your lizard should've joined debellia.
My Vampire's cheekbones clipped with Dark Brotherhood cowl. And I was on console at the time, annoying as hell. Also various boots clip with any mage outfit.