Try as seen on screen (www.asos.com or .uk, can't remember. All sorts of reasonably priced stuff and a premium section, it's bang up to date and a lot of the stuff is reasonably priced.
americanapparel.net is great, great clothes that are always in Grazia and the like.
Also oli.co.uk - again well priced and appeards in a load of mags.
Plus Gap clothes look really great this year, some of the ads I have seen the clothes look really cool (and I have always put Gap in the Next middle-of-the-road crap section). I am sure they do online shopping.
Do Marks and Spencer do online shopping? I have never bought a stitch of clothing from there, but some of the clothes on the latest telly add look nice. Am I sad and getting on a bit, or are M&S suddenly making nice clothes?