Feel Your Heart and Nazo are both so sentimental to me, I just feel really nostalgic listening to them (when they redid Nazo for opening 41 i shed a tear ngl). I like a lot of the music by Mai Kuraki, especially Revive it's a banger. Butterfly core was also one of my faves. Honestly I really like most of the openings it's so difficult to choose. In regards to endings, I never listened to a lot to be completely honest because I binged the series so I'd usually just move to the next episode or skip over to the post credits scene but the few I genuinely enjoyed were (again) the Mai Kuraki ones such as Koi Ni Koishite and Your Best Friend, and I do really like the current ending, Aozolighter.