I usually go for the fit, there a lot of off the peg clothes that just dont fit and shoes never go high enough in size for me, i do like a lot of the yank stuff, like Abercrombie, and some of the walkin gear like north face or columbia, I do find unless you get into the bigger towns and citys the high st retailers dont carry a large selection of sizes, trying to find a smart pair of 36-36 jeans and decent size 14 shoes is a nightmare, and i am to young for high and mighty, who carry an abnormally large amount of tweed.
And if i am in a jumble sale mood tk maxx is the place for last years yank gear and unsold freak sizes, me and the midgets are happy lol