My favorite VN soundtrack and quite possibly my most valued soundtracks even outside of the VN sphere. Everything about it is awesome in every respect. If I sound biased it's because I am. I love this OST to death and I love Shinji Orito & Jun Maeda for producing it.
If you liked any of these tracks you owe it to yourself to also look up the obscure fighting game Eternal Fighter Zero, a game featuring various characters and music tracks from a variety of Key games. Those tracks are all remixed and sound great, especially ridge of frozen soil saw a jazzy makeover that really took me by surprise.