Personally I like Royce for the very smooth texture (one of the series; coated with cocoa powder ones). The rest frankly speaking a bit pricey.
Usual day mostly eat Cadbury dark and Ritter Sports.

Ritter have a very wide range of choice. I like the strawberry yogurt and Kakao-Mousse flavor. The Kakao-Mousse ones rather oily texture but smooth and taste good. Not to mention it's very affordable.