Already have the big box and seaside. I doubt I will ever play with more than 4 players either, so don't necessarily need the extra victory / treasures in intrigue. and we don't mind crazy game changing cards if they can fit well with the other cards I already have. thanks in advance!
If you like crazy, get Dark Ages
If you like nice and simple, but still a nice, new concept, get Hinterlands.
If you like support cards, and some really deep strategic thinking, get Guilds