It's an open challenge to find any comedy protagonists under age 25 who don't fit this archetype in The New Tens. Over 25, it's almost always "chunky guy who needs a shave," which fits into a much broader definition of Adorkable.
Chris D'Amico/Red Mist could be a villainous example, given his love of comic books, his slight lisp and the fact that he and Dave have a silly bonding moment jamming in Chris's car while on the way to a crime scene. Unfortunately, his lovable dorkiness disappears pretty quickly afterwards.
Abe Sapien was always the smart one of the group in Hellboy, but it wasn't until the sequel he became full-on adorkable. It might have something to do with gaining his first love interest (any time he interacts with her is stuffed full of awkward), but even before that he can be seen geeking out over some rare Victorian goggles. Fangirls are split somewhat between this portrayal and the more traditionally Badass character in the comics.
Jane's usually a level-headed girl, but anytime Thor turns on the charm, she turns to a giggling school girl. Being played by Natalie Portman certainly didn't hurt.
Thor himself applies when he's on Earth. Despite being completely ignorant to how the mortal world works, he is a polite and chivalrous gentleman towards women, Jane in particular, even before his redemption. He even kisses Jane's hand and bows in farewell to Darcy and Erik for their help.
The Warriors Three and Sif demonstrated adorkability tapping on the glass window with huge grins when they found Thor.
Bill Pullman as Dr. James Harvey in Casper. Seriously, the guy wears glasses, multiple nerdy sweaters and makes several attempts to be a stern father towards Kat - all of which fail.
Griff The Invisible is probably the shyest, meekest, sweetest wannabe-superhero you will ever meet, and fulfils this trope to the point that you almost need a teddy bear while watching so you'll have something to huggle when he's sad. Also his love interest/self-appointed sidekick Melody, a klutzy but very sincere girl with no comprehension of social norms and a lot of strange psuedo-scientific theories. Watching them dash around playing superhero is cute to a possibly lethal degree.
James Spader as Dr. Daniel Jackson in Stargate. He looks cute and vulnerable, and he's a geeky and quirky linguist, specializing in ancient languages. And he wears round glasses and looks like John Lennon.
Sir Galahad the Pure/Chaste. Zoot and other ladies from Castle Antrax find him irresistible. Unfortunately, they scare him off by being too advancing (they even ask him to spank them). When he seems like he might get into the mood, he's "saved" by one of his friends.
Sir Robin the Not-Quite-So-Brave-As-Sir-Lancelot. How else do you explain that his favourite minstrels and his group still followed him, even though when he ran away from the danger instead of fighting?
Elliot from Bedazzled (2000) is adorkaable, at least at first. Although it's rather negative in that he has no friends and his co-workers actively avoid him because of it, this movie needs a diabetes warning.
Mark Ruffalo as Dr. Bruce Banner. Quiet, nerdy, wears glasses, has rumpled hair, and a slightly nervous demeanor, as he's working for a company he doesn't exactly trust, with other super-powered people who won't get along, and he's trying his hardest to stay calm and not to let "The Big Guy" out. Also, he rides a tiny motorcycle at one point. And with the return of the previously mentioned Steve Rogers and Thor, the film is just FULL of adorkable-ness.
Iron Man: Tony Stark. While he's a snarker and showboater in public, his adorkableness is on full throttle when he's around the few close people he has, teasing them and giving them nicknames. (Like Rhodey.)
Chekov, the ship's seventeen-year-old Russian whiz-kid who speaks with a funny accent, gets over-excited and runs in the most adorkable way possible. Taken Up to Eleven in the sequel, in which he gains super adorkable goggles.
"I ken do zat!"
Spock definitely has his moments, especially when he's around his girlfriend, Uhura. Helps that he doesn't seem to comprehend human sense of humour.
Uhura: Are you sure you don't want me to go instead?
Spock: That would be highly illogical as I am already outfitted-
Uhura Spock, I was kidding.
Spock: Uh... [looks adorkably confused as Uhura kisses his helmet]
Detective Alma Dray from Now You See Me when it comes to magic. She looks delighted after pulling off a card trick and claps enthusiastically during the Horsemen's show.
Elaine May's character in A New Leaf. Not only is she socially awkward, but she also forgets to take price tags off her clothes; spills multiple cups of tea in one sitting; has to be vacuumed after she eats; doesn't know how to put on a nightgown ("You've got your head in the arm hole") ... and she's a botanist.