Skyn are my favourite brand. They aren't cheap but I think they are worth it. The large is a fairly standard large. http://www.lovehoney.co.uk/product.cfm?p=22413
The trojan magnums are a nice step up in size from durex http://www.lovehoney.co.uk/product.cfm?p=2645
Ive found EXS condoms to fit very well too despite not being labled as large. http://www.lovehoney.co.uk/product.cfm?p=32297