If you've only seen what was aired on Adult Swim then I'd recommend checking out the season 3, 4, and 5 boxed sets. They contain episodes that weren't aired. I know they can all be found on Amazon, and the Viridian Collection versions are pretty cheap (cheaper than the original releases). In addition to that the first 6 movies have been dubbed and released in the US. I think they are all great.
Sadly, that is all that has been dubbed/released. I'd seek out the rest of the episodes/movies, but I'm not a fan of subbed anime.