Getting this one in under the wire as I just got home from vacation. Recs for two for wonderful vids that feature Cally:
Antebellum, by fifmeister (who also made my lovely banner!), is a deconstruction of Cally and Chief Tyrol's relationship, contrasting their early innocence with the darkness that was never far away. It's poignant and beautifully done.
On a more cheerful note,
I'm Not Here for your Entertainment, by ivanolix, showcases the combined awesomeness of Cally as well as Boomer and Tory, two other female characters who were decidedly under-appreciated by fandom and, especially in later seasons, canon as well. This is definitely one of my go-to cheer-me-up vids. :D