@malp am stiel
Try it with watching the DVDs with the O-sound and English subtitles when you don't get what they are saying on the first time. You can read along and learn how they speak certain words so the next time you will recall more of what they are saying... And the accents are so much better in the original.
Stargate is generally pretty easy to understand, even Carson. The Ultimate challenge when watching movies in the O-language are Movies like "Lord of the rings 1-3" or anything with Brad Pitt (he is barely understandable on the first time) in some movies (like snatch)