One Of The Most Comprehensive Fabric & Haberdashery Online Shops.
Great range of fabrics and very cheap but only actually useful if you don't care how accurate your colours are. Pictures of fabrics rarely match up well to ordering list, so unless you're looking for a generic white or black it's really hard to get what you need.
Also next to impossible to contact them via email, so if you're in a hurry or need to return the fabric forget it.
Cheap P&P, quick delivery. As I'm at uni and don't have much time to actually go out into town and hunt fabrics, this site is dead useful.