Mine would be
Okage Shadow King
Shadow of the Colossus
Post your favorite soundtracks for everyone to hear
Absolutely love this song. It brings back so many memories and makes me want to hug someone. You can also have the worst day of your life and this will cheer you up!
I can't say all these are Sony owned, but they do make me think of the Playstation brand when I hear them. Some of my favorites.
Valkyria Chronicles has to be one of my top 3 favorite RPG's. Just overall a masterpiece that has yet to be replicated. Also, I would have gone with that classic Socom 1 theme, but Combined Assault gets me so pumped up. Love that game (here's to hoping the Socom trilogy is coming soon!!!).