I'm starting to get into Stargate SG1, but I have not yet had the chance to see Stargate Atlantis, the spin-off series, which seems to be doing quite well. You can get Stagrgate Atlantis series 1 for £29.99 delivered from The Hut (Or Asda online) - this is the cheapest I have seen it yet. Most other stores have this item at £42+ (E.g. Amazon).
Remember the 10% quidco cashback from The Hut as well.
Details: When SG-1 discovers what they believe to be the remnants of the Lost City of the Ancients - the originators of the Stargates - Stargate Command launches an investigation. A new team of explorers, headed by civilian Dr. Elizabeth Weir, travels to the distant Pegasus galaxy, where they discover an advanced but deserted city on the ocean floor, a group of nomadic humans...and a deadly enemy that feeds on human fear!