I've been a big fan of Express Men lately. Most of their clothes don't have huge/dumb franchise logos, have nice overall graphic design, and are made of good quality cotton. High five.
Express is okay, they have some good styles and designs but I find most of their clothes are ruined by being huge. When they were less popular, their clothes fit better, but now that they're selling to everyone I swear the sizes all moved up a notch. Hopefully they'll change the fit.
anyway most of my brand stuff is... Banana Republic, Armani Exchange, and Noton. That isn't to say it's a lot though, because I got a lot of clothes from 3rd party no name street/dept. store vendors in korea.
gap for sweaters and jeans although lately all they have had are these awful two-tone jeans like the kind that were in style for girls about two years ago
banana republic if you need slacks or shirts
ragstock or similar consignment store if you need something vintage (read: even faggier than the shit you can find at gap etc)
jeans, sweaters and shirts mostly at H&M, Åhléns City or small boutiques on Södermalm like Grandpa and Sneakers n' Stuff
sometimes I buy sweaters or shirts at MQ or Brothers, but that's usually for work or for when I need something for going out, they don't have much casual stuff