order of conversation
It would be great if you could change the default order of conversations, so that instead of it being ordered by most recent activity on the thread, it was ordered by the most recent posting of conversations. The reordering of conversations as people participate on the threads is jarring, and you can always find recent activity through the Activity tab.
Doug Lee commented
See also the idea titled "Keep the messages in channels in chronological order," on which I just posted a detailed design suggestion.