Shane Gooseman, the Super Soldier from Adventures of the Galaxy Rangers. He towers over the other three (and, at 19, is probably not finished growing, either!), and can easily take the most damage. Definitely a Class 3, as he comments in "One Million Emotions" that his kind can only get "angry and mad," but was seen in "Supertroopers" being the only one of his kind that questioned his role as a Super Soldier.
Another Galaxy Rangers example: Buzzwang. While he may not be programmed for combat, it is possible that he, being a robot, is stronger then the average human.
Her original design was a large, muscly man- this is one of many Lampshades hung in 'The Ember Island Players'', where her part in a play is inexplicably filled by a burly, muscled man. (Toph is delighted.)
Later seasons swap the dynamic. Bolin Takes A Level In Badass learning lavabending giving him massive AOE attacks, emphasizing his raw power and making him the groups hardest hitter. Meanwhile, Asami's driving becomes less relevant as the group moves out of the city and the narrative starts focusing on her role as Korra's confidante and emotional support.
In Futurama when muscle or a degree of inhuman dexterity is required, Bender can be counted as a Class 5 Genius Bruiser, although he's more cunning than clever. If the problem is just with too many Badass Normal mooks, then Leela will go berserker and kick their butts with her ninja skills.
Wendy from Gravity Falls normally looks like a laid-back teen girl that happens to be Younger Than They Look due to "freak lumberjack genes" leading to an early growth spurt. Those same freak lumberjack genes also give her the power to snap a huge ex-con's arm like a twig and make her very handy with an axe.
Split between Hawkgirl and Superman (plus the Martian Manhunter when the writers remember that he can do more than just phase).
June from KaBlam!, not in terms of size, but she's definetly the toughest character.
The show King Arthur & the Knights of Justice was an interesting example, because it starred a team of football players temporarily taking the place of the Knights of the Round Table, it was unique in having about five big guys (Lineman) who were essentially interchangeable from one story to the next.
Nathan Explosion of Metalocalypse is a Class 3 if there ever was one- his growling voice, immense size, and general reputation of brutality hides the fact that, at heart, he's something of a marshmallow. Who loves kitties. And his father. And Disneyland.
Rainbow Dash from My Little Pony: Friendship Is Magic. She's as strong as Applejack, very athletic, and far quicker to request a direct, physical solution than any other team member. She also happens to be pretty dense and, to top it off, she's the Spirit of the Element of Loyalty.
The Transformers Prime team has their own Bulkhead. He's a veteran soldier with some "dirty work" in his history, but still has a gentle side.
In the original Transformers, Ironhide fits this quite well for a group much larger than 5, although there's certainly a group that's considered more central than others. Also a good example of this trope from the original would be Brawn, who despite actually being SMALLER than most of the Autobots, otherwise fits this trope extremely well.
Autobot gestalts, such as Superion, typically fall into this role by default.
Brock Samson from The Venture Bros. is a Class 3. He's got a hard exterior but he genuinely cares for Hank and Dean.