In Adventures of the Galaxy Rangers, The Series 5 Rangers: Zach (melancholic), Shane (choleric), Niko (phlegmatic), and Walter (sanguine). The series actually has very few episodes where all four are heavily involved, mostly breaking the team up into groups of two or three.
Tenzin's Children (with the exception of Rohan): Jinora (melancholic), Ikki (sanguine), Meelo (choleric).
Suyin's Children: Baatar Jr (choleric), Huan (melancholic), Opal (phlegmatic), Wei and Wing (sanguine/eclectic).
Aqua Teen Hunger Force: Master Shake (sanguine), Frylock (melancholic), Carl (choleric), and Meatwad (phlegmatic).
The Backyardigans: Pretty hard to qualify. Technically, all of them are sanguine, but Pablo is probably the most. As for the others: Tasha (choleric), Uniqua (melancholic, though not depressive, since we're talking about a little kids' show), and Tyrone (phlegmatic). Austin starts out as phlegmatic, then moving on to melancholic; these days, he's starting to become more eclectic.
The New Batman Adventures: Though they rarely all worked together in the same episode, there was still a four-person "bat family." Robin (Tim Drake) is sanguine; Nightwing (Dick Grayson) is choleric; Batman is melancholic (as if it had to be said; he basically defines the temperament); and Batgirl is phlegmatic. Catwoman was the back-up choleric; in one episode, she and Nightwing even team up because of their similar personalities.
And from Batman Beyond, we've got the Royal Flush Gang who also form a Five-Man Band with the robotic Ace (eclectic), Authoritarian King (melancholic), conflicted Ten (choleric), Queen — a proper lady who tries to keep the family united (phlegmatic), and fun-loving Jack (sanguine).
Beast Wars: The four main Maximals: Optimus Primal (choleric), Rattrap (melancholic), Rhinox (phlegmatic), and Cheetor (sanguine).
The protagonists and neighborhood kids: Ed (sanguine), Edd (melancholic/phlegmatic), Eddy (choleric), Sarah (sanguine/choleric), Kevin (choleric/melancholic), Jimmy (melancholic), Rolf (phlegmatic/sanguine), Nazz (phlegmatic), Jonny (sanguine), and Plank (eclectic).
Grojband: Corey (sanguine), Laney (phlegmatic), Kin (melancholic), and Kon (choleric).
Also, Trina (choleric), Mina (melancholic), Kate and Allie (sanguines), and Nick (phlegmatic).
A good chunk of the classic Hanna-Barbera cartoon characters that are connected to the Yogi Bear universe fit this mold if you put them together (think of all of the main characters in Yogi's Treasure Hunt minus Ranger Smith, Snooper and Blabbermouse, Auggie Doggie and Doggie Daddy with Baba Looey included). Yogi (sanguine), Quick Draw McGraw (choleric, albeit a more dim-witted and incompetent example), Snagglepuss (melancholic, although mostly in terms of mannerisms since he's much more upbeat and cheerful than most examples), Huckleberry Hound (phlegmatic), Boo Boo and Baba Looey (eclectic), and Top Cat (sanguine/choleric).
The four original Happy Tree Friends: Cuddles (sanguine), Giggles (choleric), Toothy (melancholic), and Lumpy (phlegmatic).
The four main kids on Hey Arnold!: Arnold (melancholic), Helga (choleric), Gerald (sanguine), and Phoebe (phlegmatic).
Invader Zim: Zim (choleric), Dib (melancholic), Gaz (phlegmatic), and Gir (sanguine).
The Dark Hand Enforcers (after Tohru left): Hak Foo (choleric), Chow (melancholic), Ratso (phlegmatic), and Finn (sanguine).
The heroes once Tohru joined them: Uncle (choleric), Jackie (melancholic), Tohru (phlegmatic), and Jade (sanguine).
The Jetsons: George (sanguine), Jane (melancholic), Elroy (phlegmatic), and Judy (choleric) and Rosie (eclectic).
Jonny Quest: Jonny (melancholic), Hadji (sanguine), Dr Quest (phlegmatic), Race (choleric), and Bandit (eclectic).
The seven founding members of the Justice League seem to fit this pretty well for the most part: Superman (melancholic), Wonder Woman and Hawkgirl (choleric), Batman and Green Lantern (phlegmatic), Flash (sanguine), and Martian Manhunter (eclectic).
Kaijudo: Rise of the Duel Masters has three groups:
The main trio: Ray (choleric/sanguine), Gabe (melancholic), and Allie (sanguine).
The Duel Masters: Nigel (choleric), Nadia (melancholic), Chavez (phlegmatic), Kimora (sanguine), and Jaha (eclectic).
The Choten's side: Alakshmi (choleric), Suguru/ Ken Okamoto (melancholic), The Choten (phlegmatic), Fingers (sanguine), and Heller (eclectic).
The four members of "Team Possible" in Kim Possible: Kim (melancholic), Ron (choleric), Rufus (sanguine), and Wade (phlegmatic).
King of the Hill: Hank Hill (melancholic), Dale Gribble (sanguine), Boomhauer (phlegmatic), and Bill Dauterive (choleric).
The Hill family also qualifies: Hank (melancholic), Peggy (choleric), Bobby (phlegmatic), and Luanne (sanguine).
The Land Before Time series: Littlefoot (melancholic), Cera (choleric), Petrie (sanguine), Ducky (phlegmatic), and Spike (eclectic).
Littlest Pet Shop (2012): Zoe and Pepper (choleric), Russell and Sunil (melancholic), Penny and Blythe (phlegmatic), Minka and Vinnie (sanguine).
The Looney Tunes Show: Bugs Bunny (melancholic/phlegmatic), Daffy Duck (choleric), Lola Bunny (sanguine/choleric), Porky Pig (phlegmatic/eclectic) and Tina Russo Duck (eclectic/phlegmatic).
The boys: Ralphie (sanguine), Carlos (choleric), Tim (melancholic), and Arnold (phlegmatic).
The girls: Wanda (sanguine), Keesha (choleric), Dorothy Ann (melancholic), and Phoebe (phlegmatic).
Men in Black: Jay (sanguine), Kay (melancholic), Elle (phlegmatic), and Zed (choleric).
Metalocalypse: Dethklok: Nathan (melancholic), Pickles (choleric), Skwisgaar (phlegmatic), Murderface (sanguine), and Toki (eclectic).
Mr. Bogus: In one of the rare cases that Bogus and his cousin Brattus get paired up with their enemies, Ratty and Mole, it goes like this: Bogus (melancholic), Brattus (sanguine) Ratty (choleric), and Mole (phlegmatic).
The Pie sisters: Limestone is the neurotic task-master of the family, and easily fits into Choleric. Pinkie, as the super-extroverted, knower-of-all-ponies aand Equestria's best party-thrower, fits comfortably into Sanguine. Shy and quiet Marble Pie, who rarely interacts with the others and just sets her mind to her tasks is Melancholic, and Maud's deadpan mannerisms and her interactions with the others establish her as Phlegmatic.
The Princesses: Celestia normally keeps her emotions to herself and is focused on running the country (though she occasionally lets the mask slip around Twilight), and fits as Choleric. Cadance, the pony who exemplifies the love of her own subjects and got on best with the Mane 6, even having plenty of fun helping prepare her own wedding with them, is Sanguine. Luna, desperately trying to fit in, do her duty as Princess of the Night, and trying to keep her own emotions bottled up is Melancholic. Finally, Twilight is the Princess of Friendship, even though her usual hobbies would involve a night alone with a book, and so is Phlegmatic. They fit in less rigidly than the above example by nature of being Princesses with a well-rounde set of traits each, but their most dominant traits align them to the indicated temperaments.
Oscars Oasis: On the rare ocassions Oscar teams up with the trio: Popy (choleric), Buck (melancholic), Oscar (phlegmatic), and Harchi (sanguine).
The Perils of Penelope Pitstop: Penelope is melancholic; Clyde is choleric; Dum-Dum and Pockets are phlegmatic; and the Hooded Claw (Sylvester Sneekly) is sanguine. Of the other characters: Softy (melancholic), Yak-Yak (sanguine), Snoozy (phlegmatic), and Zippy (eclectic).
Transformers has the Dinobots. Grimlock would be choleric when compared to almost any other Autobot, but amongst his own team he's relegated to leukine, with violent, sociopathic Slag as the resident choleric. The other three are fairly cut-and-dried, with pessimist Snarl as the melancholic, quiet and somewhat dim Sludge as the phlegmatic, and affable Swoop as the sanguine.
The five main Autobots of Transformers Animated: Optimus Prime (choleric), Ratchet (melancholic), Prowl (phlegmatic), Bumblebee (sanguine), and Bulkhead (eclectic).