In reply to Bjartur i Sumarhus:
> Never read any of his novels although have heard good things before. Would you say the Rougon-Macquart novels would be best read in order?
I wouldn't recommend reading them all. There are a lot of them, and some of them aren't very good. It's also notable that there is no set order to them - the order in which they were written is not the chronological order in which they are set. If you are keen to read anything, start with the classics, as have been mentioned here, and if you develop a taste for them, you can fill in the gaps as you wish. The order doesn't really matter, and the main narratives stand perfectly well without needing reference to the grander scheme.