I've decided to start a new thematic list for another one of my favorite SGA fic tropes: an Atlantis expedition that either by necessity or by choice has to fend for itself in the Pegasus galaxy.
E.g. Atlantis is on its own because Earth has been lost or is too occupied in the Milky Way, or has never (or only much later) reestablished contact in the first place, or Atlantis declares its independence, or its allegiance to one or more Pegasus cultures/alliances, or develops into a colony city in the (far) future, or the Atlantis expedition members (i.e. a large group, more than just the team) settle as a colony somewhere else in Pegasus...
So far I've listed about thirty stories, but I'm sure there must be more. If you know any not yet on my list that fit, I'd love to hear about them. The list so far is here:
SGA thematic list: Atlantis is cut off from Earth or secedes