Looking for a new Space Opera series

Hey guys – I've had some trouble finding a new series and I hope you can save me some time and money. I'm really looking for a "Space Opera" story, something with less personal stories and more grand empire and high level stories. I want to read about massive space battles between galactic empires. Here's what I've read and liked the most so far…

We are Legion(Bob) by Dennis Taylor

Rise of the Republic by Jonathan Davis (all 8 books)
The Interdependency by John Scalzi
Old Mans War by John Scalzi

On another note, my favorite video game of all time was Sid Meiers Alpha Centauri where factions abandon earth and repopulate the alien world of alpha centauri, if anyone knows of something like that I would ove to try it. Thanks for any suggestions!!!! (Bonus points if it has an audio book)