"I Borg" is the 23rd episode of the 5th season. It was written by Rene Echevarria.
The Enterprise finds a downed ship consisting of several borg, but only one survivor. Worf wants to kill it, but Dr. Crusher insists on treating it and bringing it aboard the ship for treatment. Against his better judgment, Picard agrees, but with the understanding that the borg be kept in confinement.
After it's awakening, the borg searches the walls for a slot in which he can plug into the collective. Geordi makes a food container for him consisting on energy the borg can digest. While the borg feeds, he keeps saying "We are borg, you will be assimilated."
The borg is then transported to another containment cell where Geordi can study him and determine how to implant a virus into the borg, one that the borg will take with him back to the collective. The idea is to implant a chip in him that will cause the collective to try to analyze, causing a destruction of their collective identity and eventually destroy them.
Meanwhile, Guinan, whose people were scattered across the galaxy after the borg attacked them, is upset that the captain has allowed the borg onboard ship. However, Geordi is beginning to develop a rapport with the borg and introduces him to the concept of individuality and tells Guinan the changes he sees in this borg and talks Guinan into meeting him. He even gave the borg a name--Hugh.
Behind the confinement cell, the borg talks to Guinan about loneliness after Guinan confronts him about how his collective destroyed her home and people. He recognizes that resistance is not futile and people have a right to choose not to be assimilated.
It's apparent on his own, the borg is not influenced by the collective and is now thinking more like an individual. Captain Picard decides to test this hypothesis and discovers to his astonishment that indeed, the borg is now an individual who, even after recognizing Picard as Locutus (see "Best of Both Worlds") he insists that his friend Geordi does not want to be assimilated.
After a staff meeting, Picard announces that he's reconsidered implanting the borg with the virus but feels instead that Hugh will introduce individuality to the hive and it will eventually break down but without dying out.
Hugh decides to head back to the collective instead of staying on the Enterprise because to do otherwise would put the Enterprise and the federation at greater risk.
I liked this episode because it turned a boogieman into a person who can appreciate the needs and wants of others without trying to assimilate them into being like them. I think the show's message is to look deeper into a person by finding their humanity by creating trust without judgement.