Ditto on the Arai Profile Long Oval - find a shop that sells 'em and give it a try. You may even find that the proper fit is a smaller helmet size than you think with the proper shape for your head.
The first helmet I've owned that doesn't giver me 'forehead burn' so I can wear it all day without pain. Noisier than others but I wear earplugs anyway so that helps and it certainly does vent well.
I thought I wanted an Aria until I tried it on...it had something inside that just touched the end of my nose (no it is not an abnormally long nose) and it would have drove me nuts...the Shoei fit me perfect and I find it very comfortable...try them all on before buying one