Whichever one I'm currently playing.
Overall, I think I love SotN and Ecclesia the most, as SotN is still the most beautiful and creative, while Ecclesia is challenging, intense, and has plenty of original ideas too.
Symphony is wildly unbalanced, especially once you get to the second castle, but I kind of love how insane the game becomes. If you avoid the overpowered weapons all the way through (not only the insanely powerful rare drops, but also the handful in hidden rooms that are vastly more powerful than the majority of weapons available at the time) and the magic spells (nearly all of which can be game breaking), then it's not so bad, at least for the first half, but the amazing number of options you have for every fight gives you so much freedom and control over combat that it really is amazing.
Ecclesia is, above all else, a really different experience than the other games, but just as (if not more) polished. The speed of gameplay is phenomenal, and even though Shanoa has less abilities to choose from than a maxed out Soma or Alucard, they often feel like more meaningful choices due to the resistances enemies have and the danger of their attacks. The platforming mechanics are pretty fun too, with the stretch ring spell.
Aria and Dawn are extremely polished versions of Symphony, far more balanced, but more subdued too. They still have some crazy fun, but are a bit less off the wall. Portrait plays a little with the rules and has the most references to other games, but the reuse of level themes does hurt a bit.It's still fantastic.
Circle of the Moon's challenge is addicting, and the class choices on winning radically change the game. Thief mode is by far the best, as it makes the game harder but the increased luck virtually guarantees all the cards (except the two really rare ones), and the lower stats and higher drops make you use more items and make it feel far more RPG like. It may have been a GBC upport, but it blows away all the prior GB games.
Harmony of Dissonance is just a weak, halfhearted attempt. I do love Juste's speed and power, but it's too bad the enemies are too weak to fight back. It also has the most boring enemy and castle designs. The only enemy I really liked was the armor you had to push into the gears.
