I'm looking for a 4x game. Not really picky on setting or type (IE, fantasy, sci-fi, etc)

Ideally, this would be a solo, or small group (maxed at 4), and would allow building of constructs as well as army building, diplomacy options, etc.

I would also be interest in playing such a thing - Build a nation/organisation, make deals with players and NPCs, and watch my empire grow before it falls down around me.