X/Y was actually a milestone for me, in that it presented a gym battle theme which I actually took a shine to as opposed churning out another one which I would just be totally underwhelmed by. Out of all the battle themes in Pokemon, the gym leader themes were for some reason always my least favourite - but these games have now changed my outlook, with Korrina's Mega Lucario Mastery Tower Fighting Battle Music... thing only sweetening the package. I don't think any Pokemon battle theme comes close to Iris' theme, though tbh.
Mm, XIII-2 does indeed have very unique music, and all the better for it. I actually greatly enjoy the harsh, screaming vocals in Limit Break, but I know that that particular genre of music is just far too grating for a lot of listeners. I love the subtle, lush electronic beauty of New Bodhum the most, but of course, one can't discuss XIII-2 without mentioning the frankly genius rendition of Clash on the Big Bridge included in the DLC pack. Nothing will ever top the perfection of the original version featured in V, but goddamn does the one in XIII-2 come close.
What would you say is your personal favourite battle theme - and possibly by extension, general piece of music in the FF series itself?