Highlander the Series/Characters

Duncan Macleod

Badass Longcoat
Badass Long Hair / Slipknot Ponytail
Big Brother Mentor to Richie
Big Damn Heroes: All the time.
Chronic Hero Syndrome
Cultured Badass
Devour the Dragon: in Endgame
Estrogen Brigade Bait
Hair Decorations
The Gump
Honor Before Reason
I Am X, Son of Y
Katanas Are Just Better
Nice Guy
Not Himself: The Dark Quickening.
Proud Adopted Warrior Foreigner
Real Men Love Jesus: Like Connor, is still astoundingly a devout Catholic in spite of being banished by the xenophobia of his Catholic kin.
Slipknot Ponytail
The Stoic
Straight Man
Wangst
Warrior Poet: Much like Connor, he is a patron for music, poetry, fine arts, not to mention wine and fine cooking.

Methos

Big Brother Mentor: To Duncan, when Duncan will actually listen.
Broken Pedestal
Combat Pragmatist/Fighting Dirty: Including tactics such as shooting Duncan in the back when Duncan is being a little too Honor Before Reason, or stabbing an opponent in the groin with a concealed dagger.
Dark and Troubled Past
Deadpan Snarker
Ensemble Darkhorse: Originally scheduled to die in his first episode, turned into one of the most memorable things in the show.
The Fog of Ages/Time Abyss: Methos isn't even sure how old he is. His memory goes back five thousand years and "before that, it all starts to blur." Joe Dawson describes him as "An Immortal who's so old, he can't remember the time of his birth."
Good Is Not Nice
Hidden in Plain Sight: Under the alias of Adam, he joins the Watchers, and gets himself assigned to tracking down... himself.
Launcher of a Thousand Ships
Manipulative Bastard
Mayfly-December Romance: With Alexa.
The Older Immortal
Retired Badass: Or wants to be, anyway.
Retired Monster: Even has one of the page quotes. However unlike the classic Retired Monster he is sorry and wants to atone by destroying his comrades.
Shrouded in Myth
Time Abyss
Trickster Mentor
Underestimating Badassery: Several people have underestimated him because he usually avoids conflict. In one case, a possessive immortal who hates that Methos slept with his slave tracks him down in the present day, using both Joe Dawson and Joe's daughter as bait. Said immortal thinks Methos is a weakling and a coward, and expects to easily beat him. Instead Methos curb stomps him, and the last words the other immortal hears is Methos saying "Just because someone doesn't like to fight doesn't mean they can't."
- Also, in the bad timeline shown in the last episodes where Duncan was never born, Methos went on one hell of a Roaring Rampage of Revenge when the Watchers are taken over by Horton, who begins slaughtering immortals and kills Methos' mortal lover in an attempt to get to him. Methos promptly teams back up with his old partner Kronos and begins leading the war against the Watchers. Their actions are described thusly: "They made the Russian Mafia look like choir boys."
What Could Have Been: Methos was slated to die but the producers like what the character brought to the series and he became a recurring character.
Would Hit a Girl: He has been alive for thousands of years before the idea of chivalry, after all.
- He might have done this for fun when he was Death of the Horsemen, but in the present? They're gonna need to deserve it a lot.

Amanda

Betty and Veronica: with Tessa
Classy Cat Burglar
Femme Fatale
Kill Steal: In her first appearance she decapitates a disarmed immortal seconds before Duncan would have killed him.

Tessa

Richie

Ax Crazy: After Duncan is afflicted by the Dark Quickening and tries to kill him, Richie decides to devote himself to The Game, and goes on a nationwide Immortal killing spree.
Badass Adorable: He didn't take many heads on-screen, but the Immortals he did defeat included Mako (~700 years), Ivan Kristov (~400 years), and Carter Wellan (~1000 years). And he looks like this.
Dawson Casting: Not so noticeable at first, but by the end of Richie's time on the show, Stan Kirsch was pushing thirty. Richie became Immortal at age nineteen.
Dropped a Bridge on Him
Foster Kid
Ho Yay: Something fierce with Pete Wilder in Counterfeit.
Mentor Occupational Hazard: Subverted.
Naive Newcomer
Sidekick
Street Urchin: Starts out this way.
Training Montage

Joe Dawson

Badass Normal: Even more impressive than usual as he manages to be this trope while a double amputee.
Cool Old Guy: Joe Dawson is epitome of coolness.
Gangsta Style
Handicapped Badass: Joe Dawson has no legs and can still kick your ass all day long.
Mr. Exposition
Muggles
Perma-Stubble
The Watcher: Well, one of them.

Darius

Actual Pacifist
The Atoner
Badass Preacher
Real Life Writes the Plot: Werner Stoker, the actor who played him died during the filming.
Retired Badass

James Horton

Big Bad: In Season 2.
Fantastic Racism
Manipulative Bastard
Not Quite Dead: Several times.
The Watcher: The renegade one.

Kalas

Beard of Evil
Big Bad: In Season 3.
Guttural Growler: Had his throat slashed by Mac in the '20s. He survived; his singing career did not.
Revenge by Proxy: He would kill or frame anyone who is somehow related to Macleod.