I've had massive problems with helmets as I have a weird shaped head and a very tight wallet......
I cannot stick to only having 1 helmet as I like to mix it up from time to time depending on how I feel.
I have found that only a few manufacturers make a XXL helmet that is actully XXL.
I currently have a Caberg Stunt, Bell MX-9 and a AGV K3 and a LS2 open face
Caberg, excellent. Fairly quiet and with built in sun visor and great chin fastening.
Bell, awful. Noisy, crap old style d ring chin strap and bloody expensive visor replacements.
AGV. bit tight on the cheeks, but very good quality.
I tried on more expensive helmets, but none fitted. In fact I couldn't even get an Arai over my forehead !!
All were under £100 and I would reccommend all of them, except the Bell.....