I am the direct opposite. I don't care for chocolate biscuits, cakes, ice cream (although I have sort of come to enjoy this more as I get older), whatever. If I am going to eat it, I want it full on chocolate.
I like hazelnut and chocolate bars, so usually I can't go wrong with something with that combination. However,
Fazer chocolate is my favourite. I don't know if the stuff sold in the UK is the same because I've not seen it here. Marabou is also very good.
Before I lived in Finland, I used to love Tolberone. I remember having one on the flight home and thinking it tasted pretty horrible compared to the stuff sold in Scandinavia. I guess I am not alone as many chocolate lovers prefer Scandinavian chocolate to chocolate from areas more known for quality chocolate production.
The worst chocolate, and I am talking even worse than those "chocolate flavoured" bunnies that you find in the States at Easter, was when I was given some Soviet era chocolate from some Estonians. That really puts into perspective just how bad chocolate can be.