Lancombe do some good ones. Bristle are the best, but the fibres can be made from blue sable to synthetic stuff. Whichever you choose, always wash them regularly, stroke against a towel or paper so that the fibres all lay in the same direction, and let them dry naturally.
I have a beautiful chanel blusher brush. It's probabaly the best brush I have. I have various makes but that is definitely my fave, it was a present though...my friend got a set of No 7 make up brushes and really likes them. I also agree with Katie77 that the body shop do nice ones.
I've looked at professional ones and although few are exceptionally good, most of them are just the same as the Body Shop ones. Body Shop is much cheaper!