if a film or TV show is in another language than the channel it's on, there are generally 3 types of "translations" possible:
1) they replace the spoken sound in foreign language with the translation in their own language. this is mostly done with recordings aimed at younger audiences.
2) they subtitle the entire thing, but leave the audio intact.
3) they do nothing with the recording.
which one do you prefer and why?
personally, i prefer subtitles (and even pure) over dub, for several reasons:
1) it does not disturb the original setting. especially when you're considering films with actors in several different languages, like english and chinese (some jackie chan films for instance), having it dubbed breaks the immersion.
2) you get to know the original voice actors, so the mood of the film isn't thrown away. an actor with a very gritty voice or 2 actors that sound alike (and often are chosen for that goal) adds a lot to the color of the film.
3) oftentimes, the dubbed sound does not fit the actor AT ALL. an example of this: a cartoon network show titled "cow and chicken" is dubbed where i live (belgium). chicken has a rather scraping voice in the dub, which doesn't seem the case in the original, and cow sounds almost boyish in the dub, not girly at all.
4) subtitles allow for things other than voice acting to be translated in a more immersive fashion. things like written words. sometimes, the written words are needed for the understanding of the show, but the actor is speaking during this.
5) dub often changes the order of the words, which breaks some of the jokes. for example, someone opening a bucketed door in english might sound "don't go inside through that" *bucket falls* "...door". in Dutch, that becomes "ga niet door die deur(don't go through that door)" *bucket falls* "binnen (inside)". it gives a totally different feel, and it kills the joke. with subtitles, you can just state at the bottom "ga niet door die deur binnen", ending right before the bucket falls.
6) sometimes, there's already source material that's subbed or dubbed, and choosing the opposite for another medium totally ruins it. a prime example of this is the simpsons movie in Belgium and netherlands. the original show is subbed, but for some reason, they decided to make a dubbed version of the movie as well. they think that it's a cartoon, so they should dub it for the kids, but the problem is that the original cartoon was aimed at an age group that can at least read, and possibly older, due to the nature of some of the jokes requiring at least a basic cultural understanding. for example, the movie has a parody of the al gore documentary. i doubt someone who can't read understands this. similarly, schwarzenegger being president in itself requires a rudimentary knowledge of US politics.
i'm sure i can come up with more reasons, but these are the most prominent.
the question remains: dub, sub or pure?