Actually my overall favorite so far is still the Faerun map. It's a bit largish (~400 provinces) but it's just a very very nice map for the most part, and I've had some very enjoyable SP games with Hard/Vhard research on it.
Personally I don't think I'd ever try Europia. I am sure it's a fine map, but after 8523 games of Total War, I'm growing a bit sick of (campaigning on) that particular continent.
