I find it very difficult to choose only one designer. I love both Galliano and Vivienne Westwood, but some of Galliano's designs is very tacky and un-wearable (the hoodies for example), and to be honest, i only really really love his acessories and tee's. Vivenne Westwood i simply love, especially the rockish-verybritchic-look, but as i currently only own some jewellery and a agenda i don't have much to say about the fit. It's also very special designs.
For denim, as i wear almost everyday, i only really like Cheap Monday and Acne Jeans, so in some levels i would say those, but their other clothes are very boring and not quirky.
I think the problem is to me that i love mixing looks as i hate head-to-toe, but i love Chanel, Vivienne Westwood AND Cheap Monday in three different ways so its impossible to choose, but after all, i would probably go with Viv.