Aerosmith's lead singer Steven Tyler. While not particularly tiny [he's 5'11.5" according to some sources], he's still hyper and loud and gets extremely excited about certain things he's passionate about.
A downplayed version, as he's rather mellow when he's on talk shows.
Back when he was on Freaks and Geeks, John Francis Daley definitely qualified as this. In the behind-the-scenes videos, he attempts to scare the cast by hiding in the set and launching himself at them, runs around a parking lot flailing his arms in between takes, and proclaims to the camera "Watch how quickly I can eat!" before downing a bowl of noodles in ten seconds.
John Barrowman, being six feet tall, doesn't qualify for "small" but makes up for it by checking off "cute," "colorful," "hyperactive,", and "regularly loud" in an as over-the-top fashion as he can possibly manage. Here he does a perfect imitation of a Jack Russell Terrier.
Doug Walker is this trope when he isn't playing any of his alter egos. Just watch some of his v-logs, particularly his Twilight Breaking Dawn part two review to see him squeal, yell and jump up and down in annoyance and laughter.
While known for playing intense and often disturbed characters, teen actor Sterling Beaumon is this off-screen.
Every single member of Rush. Geddy Lee mostly exhibits it onstage, with his almost-dancing and bouncing around. Alex is like this mostly offstage, always cracking jokes and trying to make everyone around him laugh. And then there's Neil. Hoo boy, Neil. He's known for not showing much expression while drumming and being notoriously reclusive and shy in his daily life... but during interviews, watch for the interviewer asking him about something he's really passionate about. (Motorcycles, books, drums, birdwatching, and good food will all elicit this kind of response.) Neil will immediately start fanboying it up, with bouncing in his seat, flapping his hands, and starting up the Motor Mouth. And then he'll catch himself, sit on his hands so he doesn't bounce or flail, and make a conscious effort to slow his speech down. (Inevitably, he will fail. And it is adorable.)
Ryan Lee, particularly in Super 8 but also in real life as evidenced by numerous interviews.
While *NSYNC were not particularly small, they made up for it by being extremely energetic on and off-stage and regularly derailed their interviews on purpose. It says a lot about them when Lance, the group's so-called Quiet One, is actually very energetic and cheerful on his own.
Willard Scott, the semi-retired weatherman for Today, is far from small (6'3'' and well over 200lbs) but more than makes up for it for his sweetness and enthusiasm. Just look at this interview with Jay Leno.