Atlantis was just starting to hit it's stride. Granted it jumped the shark a little bit when the Wraith turned into the good guys, though Todd was cool(though honestly it was more Christopher Heyerdahl than anything else that made him cool, he played him as a sarcastic SOB who was on the outs with his entire species). And it became a little derivative when the replacement bad guys turned out to be replicators, not the old replicators, but Ancient replicators so they're different, but not really. And it tripped a little when they couldn't get Torri Higginson to rerpise her role as Dr. Weir for an episode in which she appears after being thought dead as a replicator. There's a fairly long scene where the replacement actress explains why she doesn't look like herself.
But, it was a fun ride with interesting characters who were, for the most part, barely fleshed out.
And it was canceled for this tripe.