Opps cardinal sin.... I've just ordered a helmet off Wiggle, because I liked the colour!
The helmet was delivered and all seemed fine. Most of the helmets these days have that really easy adjuster at the back which allows the helmet to fit really snugly once all the straps are sorted out aswell.
But sadly had to send it back because the peak was twisted and looked like I had already fallen off in it! Hopefully replacement should be fine. But it seems to me once you know if you are a small/med or large, the helmets all seem to be pretty standard. (but I could be wrong, havent tried that many makes). And then its just a question of syle/colour etc. The one I've just got is a Met Dedalo? (but the makes didnt mean much to me, more a colour and price choice!)
Also most brands offer free replacement if your helmet gets crash damaged within a certain number of years of purchase, I think mine said 3 which is quite a while. Always worth remembering before shelling out for new one, because I know I forget how long I've had stuff once I throw out the receipt.