I use series 7 all the time, Rosemary are a superb choice.
Series 7 come to a point everytime and the bristles 'break down' at an even rate.
Rosemary Series 33 are the best bang for buck available.
Another fantastic set by Rosemary is Series 401, these are superb for block painting, base painting etc all the bits of painting you don't want to use your expensive brushes for.