Been with HSBC since I was 13, they have been spot on everytime I have needed them for something. At one point many years ago the Bank Manager of my local branch went well out of his way to threaten legal action against a Company who had taken me and my friend for a ride.
Since then i´ve had no problems at all with them, although more recently its started to bug me that they have moved their call centre to India, difficult to have a decent conversation with them now so I tend to do everything by online banking these days.
Mortgage is with Abbey, cant fault them on their interest rates, but i´d never have a Bank Account with them just purely from their treatment to friends of mine.