Hiya Bob!!
Bit of a controversial issue that... We have a
thread about the discussion, and we all have differing opinions, as you can imagine!
I'd have to say chronologically. It makes more sense to read them that way, as it places all the historical events in more or less a more understandable order.
I forgot to mention that
Wilbur Smith's main website also has a reading order, I believe it coincides more or less with ours. So you have Mr. Smith's opinion to go by as well!
Which 5 books have you read?