I tried the M&S big tin last year and wasn't keen, the chocolate was kind of fruity. I normally like M&S chocolate but they weren't for me.
For regular chocolate bars, I've started buying polish chocolate from Tesco, the Alibi Max bars, the classic one is how I remember Lion bars tasting and Knopper nut bar, they're just like our chocolate bars used to be and they're cheaper than our chocolate.