This can include any bank or building society (and even Revolut despite it not actually being a bank). It can include the online banking part of the website (if applicable) as well as the site for the bank itself (e.g. Monzo – Banking made easy)
Personally, I really like both Santander’s and Virgin Money’s websites. I think some of it does come down to the red and white colour scheme which I really like, but I do like the rest of their appearance as well. They look modern and everything is really well laid out. I’ve had no problems finding anything.
Virgin Money’s online banking also looks really nice. It has a very similar artstyle to their app which I think works well.
However, Santander’s online banking doesn’t look the best. It is quite outdated. It works perfectly well but I think the appearance does need updating.