http:/www.astroempires.com
Great galactic conquest MMO game. Build your bases and fleets, research technology, create an economy, establish trade routes, join a guild, go to war with your neighbors, the standard Star Trek type stuff.
You can play for free with a few limitations but upgrading is cheap. The best upgrade option is only 20 Euros for one year and you get 50 free game credits. There are shorter term options but they aren't very good value compared to the 1 year upgrade. Your first 7 days come with free upgraded status so you can see what it's like before you decide whether to upgrade or not.