9. Arena (The Original Series)
Plot in two lines: Kirk is left stranded on an alien world to face off against an opposing captain with only his wits to help him survive.
Why Your Trek Friend Says It's Good: Wow. One of the most legendary creatures of The Original Series vs a Gorn (couldn't resist). Yes, Captain Kirk faces off with some of his trademarked fighting moves and reinvents gunpowder into the bargain before telling another alien race where they can go because he won't do what they want him to. It's man against lizard for survival in a desert while everyone else on the ship is powerless!
Why It's Not Actually That Good: Kirk vs a man in a rubber lizard suit. This guy moves slower than a queue at a supermarket express checkout so it's no wonder Kirk can defeat him. To be fair he could just sidestep him and he'd never be on the business end of a Gorn piledriver. This is back-to-basic monster of the week stuff and perhaps not quite up to the more cerebral and thought-provoking episodes that Roddenberry was hoping to produce. It's been parodied, used in game adverts and then when CGI got clever they reinvented the Gorn not once but twice. Bless the '60's and this might be a classic but perhaps we're viewing it through rose tinted glasses?