I bank with First Direct and am very happy with them. If you have a mortgage I'd certainly suggest you think about moving to an offset loan - you don't get interest on the savings, but you don't pay interest on that part of the mortgage, so the "interest" is tax free and you save more than you would earn on traditional savings.

If you have debts you may get a better return by paying them off instead of having savings (watch for early termination charges, though). e.g. if you are paying 2% a month on a credit card, it would be better to get shot of that than earn 5% per year on savings. What you don't pay to the card each month can go in the savings account - so long as you don't go and run it up again.