There are many guest stars in Star Trek who endear themselves to the audiences, carving their own niche in the hearts and minds of those who follow the franchise. Some are purely comedic and some are pure evil. Some come down in the middle and some are in a category all of their own.
One such guest was Dwight Schultz as Reginald Barclay.
The character originated on Star Trek: The Next Generation, was featured in a cameo in Star Trek: First Contact but truly found his feet on Star Trek: Voyager. He became something of a sidekick for Robert Picardo's Doctor/Lewis Zimmerman, explained away initially in that he was a member of the team who helped to design the Doctor and then simply being accepted as an officer with an almost unhealthy obsession with the ship.
Through his various episodes, while much time is spent depicting his neuroses, the audience watches Barclay begin to emerge from his chronic shyness to become a confident and highly moral officer, one who manages to bend the rules in the name of the greater good.
The rankings for this list are not necessarily ranking the episodes in terms of their overall impact on their various series, but rather they are ranked in terms of Barclay's impact upon them.