I generally prefer subs over dubs, although there are some exceptions.
Ultimately subs vs dubs is a matter of what you're used to, and the English/other voice sounds a lot better if it's the first version you hear. The issue with the quality of Western dubs has historically been quite notable, although much less in recent years. The guys who do them have finally started realising that anime fans are an angry elitistic bunch, and they won't stand for shoddy voice overs. =P
Ben: it's not that Japanese are inherently superior voice actors... but they just are in this case. I mean, can you find anyone who's willing to say American movies don't have the best special effects? Voice acting is generally a much more of a respected and developed profession over in Japan, as the concept of what can be done with animation is a bit wider than on our side of the globe, they get paid better etc.
The West has some really good studios like Disney, but projects like dubbing over anime was almost always done as cheaply as possible with amateurs. This is much less of a problem nowadays, but the image persists, and it's not like all of those bad dubs are disappear anywhere.
