Supermarket stuff: Tony's Chocolonely salted caramel (from the Netherlands) is super, and Ritter Sport Cornflakes is nice. Lidl has a white chocolate I could eat in huge quantities and I don't even really like white chocolate that much.
For British brands — Duffy's and Damian Allsop. I think Damian Allsop's water ganache chocolate is possibly the best in the world.