These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Crowning Music of Awesome: The theme tune, considered by many to be one of the best TV themes ever. The theme song is by composer Morton Stevens. It became a hit single for The Ventures, a famous instrumental rock group.
A bit of trivia: That distinctive music that plays over the old "CBSSpecialPresentation" ident is from a cut on the soundtrack called "Call to Danger".
In fact, the show's only Emmys were for Stevens' scores to the episodes "A Thousand Pardons, You're Dead!" and "Hookman" (he was also nominated for the pilot) — and what's more, "Hookman" was up against two other episodes of the same series (Bruce Broughton's "The $100,000 Nickel" and Don B. Ray's "Nightmare In Blue").
Dying Moment of Awesome: Chin Ho, after being revealed as a Five-O plant, immediately slugs the leader in the face and then attacks the other two thugs. While he's ultimately unsuccessful at trying to escape, and the leader mocks him at what he did being a mistake, he replies that it was worth it and he doesn't think he has much left to lose. Sadly, he's right.
Esoteric Happy Ending: At the end of "Tricks Are Not Treats," McGarrett orders Chin Ho to arrest the bad guys, even though he really has zero evidence against them and knows they'll probably walk.
Harsher in Hindsight: "Paniolo" climaxes with Frank Kuakua, as the title character ("paniolo" is a Hawaiian term for cowboy) heading to the mountains he calls home, where he dies. Frank was played by Frank Silvera (The High Chapparal), who passed away in an accident in his own home not long after filming this episode, leading to a The Character Died with Him moment on his regular show.
Moment Of Awesome: McGarrett catching the villains in "3,000 Crooked Miles To Honolulu" when they're on the plane about to leave, one of many, many moments the man racks up.
Narm: The usually in-control Steve McGarrett becoming all weepy and relieved when he realises he won't be paralyzed after a car crash in "The Ninety-Second War, Part 1" ("I can move them! I can move them!"). And although it's a serious situation, James MacArthur's overacting in "Beautiful Screamer" when his girlfriend, played by Anne Archer, becomes one of the victims of a serial killer helps in no way, shape or form.