As far as Persona goes, I tend to go with the English voices, simply because that's what I'm used to from the RPGs. Don't have an issue with any of the JPN voices, though, and I'll occasionally switch to those just to hear Romi Park be godlike with Naoto.
As for BB, I'll take either. Both voice casts, aside from English Bang currently, are absolutely fantastic at what they do. Asking me to choose between Isomura and Robinson for Makoto is like asking which of my non-existent children is my favorite. Same with Vee and Kondou for Noel, and Sugita and Seitz for Rags.