Of recent reading:
Hidden Empire by Kevin J. Anderson
Horizon Storms by Kevin J. Anderson
Better be ready to spend a year to swallow these three, around 3k pages give or take a few hundred pages.
Pandora's Star by Peter F. Hamilton
Judas Unchained by Peter F. Hamilton
The Dreaming Void by Peter F. Hamilton
Also I really enjoyed the Invasion Earth series by one very under rated SF author L. Ron Hubbard. This series is NOT a difficult read but it's got all manner of good fun with politics, subterfuge, betrayal and anything else one could love in a tacky space version of a soap opera. Plus any of the 100s of the genre I've read over the years which I can no longer remember.
I am not sure if Heinlein's
Time Enough For Love is truly space opera, it's all to human with emotions and it will leave you misty eyed when you are done, a real rarity from Heinlein.
One last series from years gone my that might be more space adventure than space opera not sure if there is any difference but, hey I know about the net-nitpickers so one need, out of self preservation if nothing else to edit and qualify every figgin' comment anymore, but there was a series which long predated Star Trek that surrounded the the space career of
John Grimes who was everything from young upstart flight officer on his first ship to a Commodore to a pirate with all the tawdry relationships and adventure that went along with a colorful life out on The Rim. Just google "john grimes A. Bertram Chandler" or look here:
http://en.wikipedia.org/wiki/A._Bertram_Chandler
These also have some loose tie-ins to the
Dominc Flandry stories by Poul Andersen which are also a lot of fun. Nothing deep or introspective but more fun and escapist story telling. But still I came to care about Grimes and Flandry just made me laugh.
Oh yeah, the John Grimes and Dominic Flandry books can be had from Baen, in fact I believe you can get the Grimes series, there are three, in collections so as to keep them straight.