Ah, Baal. Sometimes an ally, usually a villain, the former System Lord is back causing havoc for our team - and the planet. And, of course, it's up to SG-1 to figure out a way to defeat him. (Maybe they should kill him this time.)
Stargate: Continuum on DVD July 29, 2008.
Also available on Blu-ray (!).
Also available is Stargate - The Ark of Truth which resolves the Ori conflict of the regular series.