I have not seen the Soul Eater series, so I don't know if I'd be able to pass good judgment on this, seeing as I've only watched one of the series that are compared. But for now I'll go with Bleach here. I've been watching the series since its first season and pretty much followed it through in the manga as well. Also in the start of my rping days I've constantly joined Bleach guilds and rp sites outside gaia, creating my own original characters based off the anime. Honestly though I'm a bit bummed with how it's still going and stretching on, following the footsteps of another anime Naruto, it would've been great if they gave some sort of closure or ending for the series. But I also appreciate the fact that they still manage to find story arcs for Bleach (I just wished they were carefully thought out plotlines to make things interesting for everyone). The concept of the anime is great, Shinigamis dealing with souls and hollows, their epic bankais, as well as the twists and developments in Sereitei. I particularly like the Quincy concept, and the Jagdarmee story arc (wish they would've broadened that one more). I will admit, despite its current dragginess, there were moment stealers here and there (like the one with Ichigo and Uryuu being brothers and Byakuya Kuchiki dying did not fail to surprise me and give me feels, among other stuff) The other races found in the series, like the Togabitos, Bounts, Vizards and Arrancars, were also pretty neat, I also just wished they gave them more exploration besides focusing on the Ichigo-turns-into-an-evil-Hollow-yet-again arc.
As for intro theme songs, Bleach actually has a LOT of them, and awesome ones too. I especially like the one with Rolling Stars by Yui, and other J-rock bands such as Aqua Times, Beat Crusaders, and Orange Range.
Quality-wise, it's a pretty good anime, what with the characters, certain arcs, and the music. So yeah, my vote's definitely on Bleach. (But I am open to watching Soul Eater when I find the time, or interest for it.)
