Tried the Honor Harrington series by David Weber?
Ripping action space opera stories in the Hornblower/EE Doc Smith Lensman series tradition - lots of battles, politics and action - and there's lots of them!
While you're there, Frank Herbert's son Brian has done a fine job expanding the "Duniverse" with well researched back stories, prequels, sequels and more. if you liked Dune but couldn't really get into the original sequels, I'd highly recommend these books by Brian Herbert.
Happy reading
Andy