There's two: One from 1989 (first distributed by Streamline), and one from 2001 (first distributed by Pioneer).
The newer one is quite a bit better in it's script and voice acting, as well as sound mixing. The 1989 dub is very dated in it's casting choices (some choices are just strange), and SOUNDS like an old dub. It has many talented voice actors, but many of them under-act or over-act, and the performances lack subtlety (they also had several voice actors play multiple roles). The script is also very confusing, and makes the film difficult to understand. While the 2001 dub isn't perfect, it's quality is much more on par with other dubs of the time, and it holds up very well (it's about as good as, say, Bleach's dub and has many voice actors from it). There are a lot of people nostalgic for the 1989 dub though if they watched the film in the 90s, where it was pretty popular here, I do recommend the 2001 dub more.
Depending on how good you are with voice actors, the original dub's cast had Cam Clarke, Jan Rabson, Lara Cody, Tony Pope, Barbara Goodson, Bob Bergen, Melora Harte, Steve Kramer, and Lewis Lemay.
The newer dub has Johnny Yong Bosch, Joshua Seth, Wendee Lee, Jamieson Price, Michelle Ruff, Michael Lindsay, Simon Prescott, Robert Axlerod, Cody MacKenzie, Sandy Fox, Robert Bucholtz, and Matt Mercer.