I have recently become a customer of Bulb for my energy. They won me because when I tried to sign up and this failed, they followed up with an email explaining

I have recently become a customer of Bulb for my energy. They won me because when I tried to sign up and this failed, they followed up with an email explaining that my existing supplier had a weird set up for my smart meter which made it impossible to take over automatically and how to get them to fix it, which appeared to have been written by a real human. In most companies, that'd just be an error in a log file somewhere. They then followed up later to ask if things had been handled well. They also have one single, good value tariff with no option not to have green energy. Principled, with A++ customer service and a competent mobile app, complete with a time line for switching and starting my account with them. I'm totally sold. They could be quite a lot more expensive than my existing supplier and I frankly wouldn't care given the whole experience so far.