By the numbers alone (and the fact that there is no hyphen) I would say the .org.
One non-objective factor is the suitability of the keyword to the .org extension. Even if .org long lost it's real-world status as a non-profit organisation ... it still retains some of that feel with many end users.
We've done well (both in terms of
SEO, and customer conversion) using .orgs - but it was with pretty suitable keywords and terms.
Cheers,
Rob