For Panzer General (and Allied General) there’s Panzer General Forever. (The developer of this remake later started his own company and developed Panzer Corps, a spiritual successor to Panzer General).

Ace Combat, mainly Ace Combat 5 but all of them are well known for their soundtracks.

More recently WARNO has excellent music so far, even though most of it was licensed by Eugen from third parties so it doesn’t really count as a soundtrack specific to the game.