Dominions.  I have bought both, and both are complex, fun games.  But much of Dominions II's complexity is hidden beneath the surface, while SEIV is more openly displayed.  Any 2 games of dominions 2 will be quite different, even if you strive to play by the same formula.
Besides, Stars! is way better than SEIV.  So who has a beta Version of stars supernova for me ?  
