For me it probably would be Sophisticated Fight and The Glint of Cold Steel. Get Over the Barrier has a lot of charm but at this point I think about that one more as a boss theme. May have to add CS2's theme to that list as it's growing on me fast. It's really good, if a little too synthesised.
On that front, started CS2. I'm a little too hooked right now. I hope it fades away a little, otherwise I'll finish the game before I save up enough for CS3.