No scrap that Batman TAS. I don't think i can choose a favorite. if i strictly stick to intros i can't post some of my favorites which played after the shows ended. I am guessing that they don't play such things nowadays. A few days ago i was watching Thor Ragnarok on TV, and i wanted to watch the end credits. They were so eager to advertise the upcoming movies that all throughout the credits they played the ads while bringing down the credits to half the screen. They played the ads even over the end credit scenes annoying me.
Anyway back to this ending song. Cardcaptors had a lot of good songs. But my favorite was this. It puts you in a good relaxing mood after all the stuff that happened in the episode.