If you are looking for classic clothes with a modern look, COS is the place.
The lines are simple and elegant and can be easily dressed up or down, and most of all, it's not extortionate. A nicely cut thin corduroy jacket with double vents and two buttons will set you back about £100. Trousers are between £40 and £60.
The shirts are great: they actually come in collar sizes, are beautifully finished and are only about £35 or so (with two spare buttons and collar bones which come in a mini pouch made of the same fabric attached!). They are slim-fitting and feel great on.
Their focus on quality at affordable prices is just what they offer -- this is a far cry from H&M who owns the chain.
Coats are about £150, jumpers about £60. This is really a great place to shop, especially for men -- I think there is a big shortage of mid-priced, simple and stylish men's shops in London and COS definitly fills that gap (think upmarket Zara at similar prices but more stylish and better quality by far!)