G&B 85% is my favourite of the supermarket brands. Cheap at the moment in Waitrose too! There is another organic offering that my local indie wholefoods shop does, can’t remember the name at the moment – it’s very nice but I rarely buy it as it’s twice the price of G&B.
IMO anything under 80% is just sugar with a bit of cocoa chucked in. Which is fine for “those people” I suppose. You know, the ones who ruin coffee by putting milk in it. 😆
The Aldi one (Moser Roth) is really rather good, they do a 5 bar pack that helps to stop me eating the whole lot at once.
I tried the strong one and it was really tasteless. Not impressed. Perhaps the others taste better (but see above!)