Please add to this list
http://www.sherwoods-photo.com/
http://www.warehouseexpress.com/home/default.aspx
In the USA I've had good luck with
EagleOptics.com
CameraLandNY.com
BuyDig.com (which are another name for another company ...) for the odd EOL product.
NetShops.com (which own binoculars.com but often have netshops discount coupons that you can use through the netshops.com site)
Adorama.com (often very good prices and quite quick but a bit opaque)