Emotional Bruiser: Despite being a total Badass, Steve does not even try to hide his affection and protectiveness towards those close to him. The Man Hug of relief is a common reaction on his part to friends surviving deadly danger.
Magnetic Hero: By the season 2 premiere all the original members of Five-0 have clearly indicated their first loyalty is to McGarrett. Even Kamekona is willing to enact a Bolivian Army Ending if Steve gives him the word.
Trauma Conga Line: Pretty much his life from the first episode on. His father is murdered while he's on the phone with him, he learns 20 years later that his mother was also murdered, discovers the real reason his father sent him away after his mother died, he's betrayed by a former member of his SEAL team who shoots up his house and tries to kill him, his sister is kidnapped over his continuing of his father's investigation, he's framed for murder by his boss, then discovers that she was Evil All Along and only started 5-0 to keep him occupied, then he gets framed for her murder and sent to prison where he gets shivved by the guy who killed his father, and most recently he was betrayed by a former 5-0 teammate and turned over to Wo Fat who had him beaten and tortured for information he doesn't have. It's been a rough year and half for Steve McGarrett.
Formerly of the Newark, New Jersey Police Department, he transferred to Honolulu PD after his ex-wife Rachel took their daughter there. He insists that he hates Hawaii and only tolerates it because it's where his daughter is.
Hollywood Atheist: Discussed in "Ka Iwi Kapu" to the disbelief of Steve. Doesn't really believe in any higher being or spirits, let alone ancient Hawaiian beliefs. Or at least until the end of the episode
Took a Level in Badass: Danny's competency as a cop is often overshadowed by Steve's extreme amounts of badassery, Chin's disgrace arc, and Kono's Fanservice and Badass. But in "He Kane Hewa'Ole", he is the first one who correctly deduces the culprit's plot. Lampshaded by Steve, who asks, "When did you get smart?"
Generation Xerox: Queen Liliʻuokalani, of the House of Kalākaua, was overthrown from the Aliʻiōlani Hale. Kono Kalakaua polices the state of Hawai'i as part of the 5-0 taskforce operating out of Aliʻiōlani Hale.
Kick Chick: She's usually seen using all sorts of kicking techniques when taking down perps.
It Gets Easier: Glossed over. Kono is introduced as a green cadet, fresh out of the academy, but almost instantly is killing bad guys with the veterans (including one with a decidedly non-regulation neck snap in episode five). Compare with Rookie Blue in which a big deal is made of a young officer's first kill. (Of course there is also the slightly disturbing possibility that she's already had experience in this sort of thing...)
Ms. Fanservice: Especially in early episodes. Her role as this has toned down somewhat since Katherine joined the cast.
Adorkable: His general attempts at courting Sabrina are so obviously over-eager that it's endearing (to both the audience and her).
Ambiguous Disorder: Introduced by the governor with the line "They say he's a savant" and had to fire his piano tuner because he liked to chat and Max found it "emotionally draining". In his off time he investigates cold cases and makes pickles, but doesn't trust phones or watch the news because it's scary.
Happily Adopted: Seems to be on good terms with rest of the Bergmans. Presumably knew he was adopted from an early age, as he's clearly Asian and "Bergman" is a very non-Asian name, though we've never seen his parents on screen to confirm their ethnicity.
Rich Bitch: Averted. In early episodes where she is The Unseen her off screen actions and Danny's descriptions lead the viewer to believe she is this, but when she's revealed she is quite reasonable and pleasant once she realizes Danny isn't jerking her around. Danny claims she left him because he wasn't wealthy enough, but she indicates to Steve that it had more to do with not being able to handle the stress of having a husband whose job puts him in constant danger.
Eternal Love: Discussed. Max says if there's ever a Zombie Apocalypse and he gets bitten, he wants her to kill him before he turns. She responds that she'll just make him bite her so they can "live forever, eat brains, and have zombie babies!"
Satellite Love Interest: All we know about her life outside dating Max is that she's a bank teller, and we only know that because that's where he asked her out.