Some suggestions, obviously pick which ones (if any) you want. There are likely some of these already. Only 1 song per soundtrack is a crime for many of these, so I'd say check out the soundtracks if you like any:
- Call of Duty: World at War (ton of good songs)
https://www.youtube.com/playlist?list=PLBEAE1D66443B7082

- Blazing Angels: Squadrons of WWII
https://www.youtube.com/watch?v=CoA-pXXuMNQ

- Brother's In Arms: Hell's Highway
https://www.youtube.com/watch?v=a7F3OXtMc9Q

- Call of Duty WWII
https://www.youtube.com/watch?v=XcHDVwL-1W8

- Letters From Iwo Jima
https://www.youtube.com/watch?v=wSGva04yOic

- The Pacific
https://www.youtube.com/watch?v=0P47yvI7SWM

- Call of Duty 2 (also a number of good songs there)
https://www.youtube.com/watch?v=d91p6RXYbeE

- Medal of Honor European Assault
https://www.youtube.com/watch?v=1n-uWmgOm9g

- Medal of Honor Airborne
https://www.youtube.com/watch?v=dCc_51wSPtQ

- Das Boot (for the submarine bois)
https://www.youtube.com/watch?v=vfbAc-H44Uw

- Darkest Hour (good soundtrack)
https://www.youtube.com/watch?v=82oX4I5gOsA

- Patton
https://www.youtube.com/watch?v=iN7uEEiT43Q

- A Bridge Too Far
https://www.youtube.com/watch?v=crqOp2zT2YE

- Stalingrad
https://www.youtube.com/watch?v=YdvP_2hVE04

- Call of Duty 3 (another good soundtrack)
https://www.youtube.com/watch?v=88bMlnfq17s

- Company of Heroes 2
https://www.youtube.com/watch?v=9eKbJJ1I1Jg

- Red Orchestra 2
https://www.youtube.com/watch?v=gSqlfUMdkMA

- Rising Storm
https://www.youtube.com/watch?v=qPfmBCWTrao

@Pumba70
Thanks a lot bro, i refer your list on making my mod!

Noiccce, not saying my list is the definitive one, but I'm just hear to put out some ideas

https://www.youtube.com/watch?v=IHZv4Cw2ZEc

I has some ideas here:
Some of the playlists will are of all the music for a given title - so there may be short tracks you wouldn't want to include in it.

silent hunter 3 & 4
https://www.youtube.com/playlist?list=PL18DD858FF9EE5B43
https://www.youtube.com/playlist?list=PLXqiX0h6ZvB_seCuC6B5fVlOWWCmuoQ84

Unity of command 1&2: (cant find any playlists with all music for this one)
https://www.youtube.com/watch?v=mX6iBJ2kxtQ
https://www.youtube.com/watch?v=1s0qlOWwrdo
https://www.youtube.com/watch?v=1s0qlOWwrdo

battlestations pacific
https://www.youtube.com/playlist?list=PLD89bydqttV74mUX85XEtXEUZUYSd6zFC