Oh and don't forget, we have some amazing map-makers out there, designing custom maps, and even whole scenarios to go with them. Not quite my sort of thing, but amazing efforts, and really valuable to have access to.
__________________
You've sailed off the edge of the map--here there be badgers!
Don't forget Dominions 3000, a mega-mod which seeks to transform Dom3 into a sci-fi game....
The continuing (and free) patches from the developers add new content. Most other games would bundle that content into an expansion pack and charge $30 or more. Add the plethora of mods & maps, and Dom3 is the gift that keeps on giving.