Absolutely, I'd love to bubble up old threads that have gotten buried.
My thoughts, in addition to coming up with the criteria, would be to have a nomination period and process (which may involve posts in each subforum, maybe we need to work with the mods) and a voting process.
If people don't abuse the system:
Nominations - simple surveymonkey survey posted here. Respond with your OS username and a link to the thread you nominate + a description of why you nominated it. Maybe we allow 3 nominations?
Selections - perhaps threads that pass a certain threshold of nominations (like 5) make it to the final phase, where we put all up for a vote and the top 2 or 3 make it in.
Alternatively, we could have 1 dynasty from football, 1 from basketball, and 2 from baseball, hockey, other, and coaching make it in each year, or something like that. Or maybe we do it every 6 months.
If people abuse the system and stuff the ballot box, we could find another, more stringent, way to do this all on OS.