The best mod in my opinion is the Real Earth Maps mod. It includes not just the Tiny/Small/Standard/Large/Huge maps with ACTUALLY REALISTIC spawns (hint hint Fireaxis), but also a small variety of other maps as well: Skirmish for balanced small battles, Ring (although I find the distances on that map inconquerable), Four Corners for round-robin, Great Plains, Ice Age, Highlands, Inland Ocean, Tiny Islands, Inland Lakes...
And all of them are computer generated (ae not "stock"). I love that mod =)