It really depends on the series for me, like in some cases I can watch both. For some series, it has nothing to do with the voices and everything to do with the translations, or how they renamed the characters, for example in Detective Conan, I liked the dubbed voices but I didn't like how they renamed the character, especially since some of the names were ones I didn't like. Where in Dragon Ball/Z/Super I preferred the dub because of the voices, but also because Goku was less of a jerk. However, would watch both. Where back before any information came out about Vic, I loved both the sub and dub of Full Metal Alchemist/Brotherhood, and would watch them interchangeable.