Crimson Belvedere ~ Eastern Dream will always be the one for me. I just.... love the EoSD ending. It's just somewhat relaxing after such an battle against Remilia. I will probably always remember what it felt like, to gain my first EoSD lunatic 1CC. I was alone in this same computer class I'm writing this post from, it was getting somewhat late in the evening and everyone else had left to their homes to spend their lives doing something else than sitting at the school's computer class. So, back to the point, I was alone, having probably my worst run of EoSD ever. I had decided that it would be the final run of the day, the final attempt before I'd leave for home. I had something like two to three lives entering stage 6, and I was rather hopeless. Back then, I had ever probably captured only one card off Remilia, so my run was basically doomed. I had had trouble beating this boss in practice mode, gaining extends through the fight, how the hell was I supposed to beat her without the two extends and a bombspam?
..
Everything went as swiftly as possible. I didn't die to Eternal Meek (I died to the noncard before it, IIRC) and I miraclously succeeded to defeat Remilia with a... bombspam at her two final cards. Nevertheless, I beat the game on the hardest difficulty, for the first time. It was raining outside, raindrops were falling on the windows. And I'm.. unsure, but I might have shed a tear or two, while listening to the awesome ending theme.
And, while I don't get the awesome feeling to that extent nowdays, I still get a somewhat nostalgic feeling, hinting back towards it. So, yeah, I'm picking the EoSD one.