GalCiv II is probably the best of the current 4x space games but here are some additions that might be nice. 1. Leaders for ships and planets. These characters give more character to the game. 2. A spreadsheet view for colonies to make managing them more efficient. 3. More cool stuff for the good guys to help balance them against evil.
I just started playing GalCivII and just won my first DL game by conquest. What victory you choose probably depends on the situation but conquest seems the quickest. edit: My second victory was playing as Humans using Influence. It seemed easy enough but it was only normal difficulty. The evil races got boxed in early on and wiped out about mid-way into the game by me. After that it was just a matter of using influence starbases, researching influence techs and building lots of contruct
