I haven't read any of the Terminator novels but maybe I can help with the Star Wars ones.
As said before, you can't really go wrong with the Timothy Zahn Trilogy for post ROTJ novels. I also really enjoyed the Republic Commando novels you mentioned, easily Traviss' best work in the EU (Expanded Universe, in this context basically the novels). Shatterpoint (with Mace Windu) and the MedStar books (kinda like MASH) are also good reads and are also set in the Clone Wars era.
For more stuff set after the movies, I can heartily recommend the 9 X-Wing novels by Michael Stackpole and Aaron Allston. The Jedi Academy books by Kevin J. Anderson are IMO not very good, but contain a lot of important plot points for the rest of the EU. As a point of caution, I would avoid any Star Wars novel written by Barbara Hambly, they are really awful.
The New Jedi Order series of books (NJO) is also really good. It contains 19 books and is set around 25 years after 'A New Hope'. And it contains the (IMHO, of course) best
Star Wars novel out there, 'Traitor' by Matthew Stover. When I first read it, it almost literally blew my mind and it is also one my favorite books of all books not just Star Wars novels.
I also wouldn't read past the end of the NJO since it all really turned to shit after that. The Dark Nest trilogy was Ok, the Legacy of the Force 9 book series was pretty awful and after the last book in that series 'Invincible' I stopped reading (new) Star Wars novels altogether.
Well I hope my ramblings are of any help to you, if you have any further question, please don't hesitate to ask