Stargate: Every Series And Movie Ranked Worst To Best

Season 3 of Stargate Atlantis seriously kicked things up a notch with the discovery of the Pegasus Replicators (also known as the Asurans), who become a principal danger to Atlantis, culminating in a truly ingenious attack and desperate escape in the season finale 'First Strike'. Before we get there, however, we have Lucius Lavin (the adorable Richard Kind) cropping up for a few humorous episodes, as well as the introduction of Jeannie Miller, McKay's sister, played by... McKay's sister.

In the seminal 'Common Ground', Sheppard is kidnapped by old enemy Kolya and meets his future Frenemy Todd the Wraith, the Wraith ally that Michael could have been, but chose not to be. While there's a lot to love in this season, the two-parter in the middle, 'The Return' was singularly rubbish in almost all regards, dragging the rest of the season down a little.

A ship full of Ancients are discovered while the inter-galactic gate bridge (genius idea) is being built and they happily turf everyone out of Atlantis and die a few minutes later. Kind of utterly redundant and a major disappointment for the hopes of seeing more of the actual Ancients showing up at any point in the future.