I think fermentation and radioactive beaches are my favorites. From a thematic perspective, I don't have the brains to actually have an opinion on whats most likely or correct.
Fermentation is funny & resonates with how fermentation is the most important chemical process to civilization
Radioactive beaches are nice if we ever manage to destroy all life in thermonuclear war, dust to dust, radioactive beaches to radioactive beaches.
edit: Creation Myths are acceptable
Panspermia doesn't really answer how life itself comes about though, just how life ended up on Earth.
but it does explain how it ended up here, like how the big bang explains how matter ended up here but not why
That's what I said!