If electoral systems interest you, I highly recommend William Poundstone's "Gaming the Vote: Why Elections Aren't Fair (and What We Can Do About It)". It focuse

If electoral systems interest you, I highly recommend William Poundstone's "Gaming the Vote: Why Elections Aren't Fair (and What We Can Do About It)". It focuses on the USA, so it's maybe better appreciated by American readers, but I found it highly entertaining and edifying, as I have several of the author's other works.