As an urban go-er, travel around by public transport and like/have to carry many many things with myself .. I'm quite crazy (and picky) about bags. Finding a good ready-made bag that exactly suited your style+lifestyle is a very difficult task, if not impossible.
For the one that I use now (bought from MUJI), I quite like everything about it, color, design, style, material, function, ... but it's not waterproof and not designed to well protect my laptop.
Recently, there're a lots of bag manufacturers who offers a custom-made of your choice.
I think I will try to have one. Well, if I have enough time -- looks like it require a lot of time in order to get a right combination -_-"