OT in Luke 1
You'll notice in the sidebar that I found 177 trans-testament references in my Scripture reading today. That's not a mistake.
Over 150 of them are from the 80 verses of Luke 1, which I found during this past Advent, studying for sermons.
Of course, that includes the Magnificat, Zacharias' prophecy, Gabriel, etc., but still, that's an amazing amount of linkage from OT to NT.