Bonanza: Ben (choleric), Adam (melancholic, "Candy" and Jamie also fit as this), Hoss (phlegmatic), and Little Joe (sanguine).
Bonekickers: Magwilde is Melancholic, Ben is Choleric, Dolly is Sanguine and Viv is Phlegmatic.
On Boy Meets World, the four main characters generally fit this schema, though it took them a couple of seasons to get there: Eric (sanguine and how!), Shawn (choleric), Topanga (phlegmatic), Cory (melancholic), and Mr. Feeny (eclectic). Early on, Topanga was sanguine, Cory was melancholic, Mr. Feeny was phlegmatic, and Eric was eclectic.
The teachers: George Feeny (melancholic), Jonathan Turner (phlegmatic), and Eli Williams (sanguine).
Other characters: Morgan (choleric), Rachel (melancholic), Minkus (phlegmatic), Angela (sanguine), and Jack (eclectic).
Girl Meets World: Maya (choleric), Lucas (phlegmatic), Riley (melancholic), Farkle (sanguine), and Zay (eclectic).
Burn Notice: Jessie (choleric), Michael (melancholic), Sam (phlegmatic), and Fiona (sanguine).
How I Met Your Mother: Ted (eclectic), Marshall (phlegmatic), Robin (melancholic), Barney (sanguine), and Lily (choleric).
I Dream of Jeannie: Jeannie (sanguine), Tony (choleric), Roger (phlegmatic), Dr. Bellows (melancholic), and Amanda (eclectic).
I Love Lucy: Ethel (phlegmatic), Fred (melancholic), Lucy (choleric), and Ricky (sanguine).
iCarly: Carly (sanguine), Sam (choleric), Freddie (melancholic), whilst Spencer fits into phlegmatic by way of being an artist who rarely interacts with anyone apart from the rest of the trio (his sister's friends), and his one single friend, Socko.
Impractical Jokers: Joe (choleric), Q (melancholic), Sal (phlegmatic), and Murr (sanguine).
The Inbetweeners: Will (melancholic), Jay (choleric), Simon (sanguine), whilst Neil is phlegmatic.
The four surgeons keep this up throughout the series. Despite the replacement characters all being vastly different than their predecessors, they still fill the spots left open: "Hawkeye" Pierce (the constant sanguine), Blake/Potter (choleric), Burns/Winchester (melancholic), and "Trapper" MacIntyre/B.J. (phlegmatic).
Other characters: Klinger (sanguine), Margaret "Hot Lips" (choleric), "Radar" O'Reilly (melancholic), and Mulcahy (phlegmatic).
The Match Game (1970s version) on CBS: Gene Rayburn (choleric), Brett Somers (melancholic), Charles Nelson Reilly (phlegmatic), and Richard Dawson (sanguine).
The McCarthys: Ronny (phlegmatic), Gerald (melancholic), Sean (sanguine), and Jackie (choleric).
The Mentalist: Jane (sanguine), Rigsby (choleric), Lisbon (melancholic), Van Pelt (phlegmatic), and Cho (eclectic).
Merlin: Morgana (choleric), Merlin (melancholic), Guinevere (phlegmatic) and Arthur (sanguine).
Monk: Monk (melancholic), Stottlemeyer and Sharona (choleric), Disher (sanguine), and Natalie (phlegmatic).
The Muppet Show Kermit (melancholic), Fozzie (sanguine), Piggy (choleric) and Gonzo (phlegmatic).
The Mythbusters: Tory Belleci (sanguine and choleric), Jamie Hyneman (choleric and melancholic), Grant Imahara (melancholic and phlegmatic), Adam Savage (phlegmatic and sanguine) and Kari Byron (eclectic).
The Mystic Knights of Tir Na Nóg: Deirdre (air — sanguine) Rohan (fire — choleric), Angus (earth — melancholic), Ivar (water — phlegmatic), and Garrett (forest — eclectic).
NCIS: Gibbs (choleric), Tony (sanguine), Kate and Abby (melancholic), Ziva (phlegmatic, though a bit Trigger Happy), and McGee and Ducky (eclectic).
New Tricks: Sandra (choleric), Brian (melancholic), Jack (phlegmatic), and Gerry (sanguine).
Noah's Arc: Ricky (choleric), Chance (melancholic), Noah (phlegmatic), and Alex (sanguine).
The O.C.: The four main teens form one: Ryan (melancholic), Seth (phlegmatic), Marissa (choleric), and Summer (sanguine). And while they don't appear together, Ryan's major love interests also make a good fit: Marissa (choleric), Lindsey (phlegmatic), Sadie (melancholic), and Taylor (sanguine).
The four leads in the U.S. version fit this trope: Pam (melancholic), Jim (phlegmatic), and Michael and Dwight crank up the most dysfunctional aspects of sanguine and choleric respectively.
The same could be said for Dawn, Tim, David, and Gareth, their U.K. equivalents.
The five original main characters of One Tree Hill can be characterized this way: Lucas (phlegmatic, or alternatively melancholic), Nathan (choleric), Peyton (melancholic, or alternatively phlegmatic), Haley (eclectic), and Brooke (so sanguine).
Only Fools and Horses: Rodney (sanguine), Del Boy (choleric), Grandad (melancholic), and Uncle Albert (phlegmatic).
Other characters: Sembene (phlegmatic), Dorian Gray (choleric), Brona Croft (sanguine), and The Creature a.k.a. Caliban (melancholic).
The original cast of Poirot fit nicely: Hercule Poirot (melancholic), Chief Inspector Japp (choleric), Captain Hastings (sanguine), and Miss Lemon (phlegmatic).
The eponymous characters in Pretty Little Liars are almost a textbook case: Aria (melancholic-p), Spencer (choleric-m), Hanna (sanguine-c), and Emily (phlegmatic-s).
For that matter, the main character's primary love interests are also a pretty good example: Ezra (sanguine-p), Toby (melancholic-c), Caleb (phlegmatic-m), and Paige (choleric-s).
Project Runway: Tim Gunn (phlegmatic), Michael Kors (choleric), Heidi Klum (sanguine), and Nina Garcia (melancholic).
Psych: Shawn (sanguine), Gus (phlegmatic), Juliet (eclectic), Lassiter (choleric), and Mr. Spencer (melancholic).
The four kids on the NBC Punky Brewster episodes (Allen departed at the start of season three when the show went into first-run syndication): Punky (sanguine), Margaux (choleric), Cherie (melancholic), and Allen (phlegmatic).
Pushing Daisies: Ned (melancholic), Chuck (phlegmatic), Olive (sanguine), and Emerson (choleric).
The five original male leads in the US version of Queer as Folk, especially in the first season.
Phlegmatic: Justin — He tends to be the most level-headed of the group, even though he is the youngest. In the Michael-Brian-Justin triangle episodes, he acts as peacemaker in the aftermath of Michael's surprise party.
Choleric: Brian — The most sexually aggressive and impulsive in the gang. His behavior is difficult to predict, and swings from irresponsible (leaving Gus with Justin to attend the Leather Ball) to heartwarming (appearing for Justin's prom).
Sanguine: Emmett — Lumberjack party!
Melancholic: Ted — Shy, withdrawn, and pessimistic.
Electic: Michael — The main character. He tends to be very passive (and would perhaps not be nearly as likable if not portraited by the charismatic Hal Sparks).
The main characters of Raising Hope seem to fit: Jimmy (phlegmatic), Sabrina (melancholic), Virginia (choleric), and Burt (sanguine).
Ravenswood: Caleb (choleric), Miranda (sanguine), Remy (melancholic), Luke (phlegmatic) and Olivia (eclectic).
Reba: Reba (eclectic), Kyra (choleric), Brock (melancholic), Cheyanne (phlegmatic), and Barbara Jean and Van (sanguine).
Red Dwarf: Rimmer (choleric), Kryten (melancholic), Lister (phlegmatic), and Cat (sanguine).
Terminator: The Sarah Connor Chronicles: Sarah Connor (sanguine), John Connor is choleric (though doesn't get the full measure of his leadership until the end of the second season); Cameron (melancholic), Derek Reese (eclectic); rounding out the group is Charley Dixon, who is phlegmatic.
The Sarah Jane Adventures - Season One: Sarah Jane (choleric), Luke (melancholic), Maria (phlegmatic), and Clyde (most definitely sanguine). However come Series Two when Maria leaves, Rani becomes the choleric (bucketfuls of ambition, and just look at how she bosses the boys about!), making Sarah Jane melancholic, and Luke phlegmatic (bless his cotton socks). This is something that makes the show very different from others: the leader of these True Companions is not the choleric character, but the melancholic one! True, Sarah Jane is still a little bit choleric at times (coz she's their leader) but she's quiet and independent, and completely occupied with all that's wrong in the world. Not to mention the shedload of melancholic moods she goes through due to all the stuff that happens to her in each series (do the writers hate her?). Effectively making this team leader the woobie.
Scrubs: J.D (melancholic), Elliot (choleric), Turk (sanguine), Carla (phlegmatic), Dr. Cox and The Janitor (eclectic).
In Sex and the City, Miranda Hobbes (choleric), Carrie Bradshaw (melancholic), Charlotte York (phlegmatic), and Sam Jones (sanguine).
The Strike Team from The Shield exemplifies this (and then some): Vic (choleric), Ronnie (melancholic), Shane (typical sanguine), and rounding off with a phlegmatic Lem.