Keiki Kobayashi, probably one of the world's best composers, became a huge part of the Namco Sound Team during Ace Combat 5. Here is a good example of his work, from the Ace Combat 6 OST.
A different version of this track can be heard in Mission 12 of Ace Combat 6 as well.
Tetsukazu, one of the oldest members of the Namco Sound Team, is an excellent composer, especially with electronic and orchestral tracks. He did most of the songs in Ace Combat 6, along with Keiki Kobayashi and a few others.
Here is Sipli Field, which plays in Mission 3 of Ace Combat 6.
A unique track from Hiroshi Okubo, one of the oldest members of the Namco Sound Team.
Using synths and orchestra that I have never seen used together, he composes a fitting track for one of the major turning points of Ace Combat 5. The song plays in Mission 24 of the game, where you have to face one of the most different enemies in the entire series.
Composed by my favourite composer, Keiki Kobayashi. Responsible for most of the tracks in Ace Combat 5, the soundtrack is one of the best of all of the Ace Combat games.
Here is Rendezvous, played in Mission 5 of Ace Combat 5.