My personal recommendation would be Joan J. But Paulh put up a list in response to your question and to be honest if you chose any of those I am sure you would not be disappointed. They all have the basic attributes you are looking for, being autumn fruiting, productive and good flavoured. The RHS award of gardening merit is only given to varieties that are thoroughly deserving. After that it is very much down to personal taste, as even tiny differences in sweetness, acidity and flavour can suit one person's palate rather than another's.
