Re: Stargate to receive movie reboot, trilogy planned
SG-1 had a recognizable ratings drop in season 10; Atlantis experienced declining viewership beginning at the same time (season 3).
That would have been in 2006, in which all three of Sci-Fi's flagship shows (SG-1, SGA, BSG) saw a decline in ratings. Which likely had something to do with Sci-Fi messing around with its successful Friday night line up.
"Internet message boards aren't as funny today as they were ten years ago. I've stopped reading new posts." -The Simpsons 20th anniversary special.