Best of Both Worlds
Best of Both Worlds part 2
Just these. I was going to add the other Borg episodes but they'd actually be detrimental to your viewing as you'd be wondering why the Federation are suddenly concerned about sending Picard to fight the Borg when they've already ordered him to post-Best of Both Worlds.
Or where Picard's weird obsession and grudge has come from when in the previous Borg encounter he barely acknowledged they were even there.