Allison Jones has a thing for nerds. The Emmy-winning casting director isn't sure why, but she gets a little giddy when someone smart, offbeat and goofy walks into her audition room.

"I just can't get enough of them," she tells The Hollywood Reporter. "They're pure souls and they try hard and they get shat on when they shouldn't."

Jones fell for a scrawny, bespectacled Christopher Mintz-Plasse after he faxed her his headshot, and cast him as McLovin in Superbad. She called Rainn Wilson a "home run" when he tried out for The Office's Dwight Schrute and earnestly deadpanned his way through a monologue about urine. And Samm Levine landed his role on Freaks and Geeks, in part, because of his terrible William Shatner impression. (Watch, below.)

Jones' résumé is jam-packed with one iconic show after the other — NBC's Parks and Recreation, HBO's Veep andCurb Your Enthusiasm to name a few — and she has the uncanny ability to find actors who feel like real everyday people. She isn't particularly interested in Hollywood glamour types, and, frankly, finds attractive people a little boring. "In many, many cases, looks and humor don't go together," she says. "It's always a compromise if you go with the beauty queen and she's just not very funny. It hurts your project."

Jones knows funny. She got her start as a casting assistant on Golden Girls, and spent the '90s assembling the core casts of hit network television shows Boy Meets World and Fresh Prince of Bel-Air. She was fresh off working on the teen sci-fi drama Roswell — more beautiful people, Jones notes — when she got a call from writers Judd Apatow and Paul Feig about their upcoming pilot.

Jones had met Feig while he was working as an actor ("He used to come in for, God bless him, the nerdy roles"), and they would go on to collaborate on a slew of high-profile films, including Bridesmaids; The Heat; and the upcoming A Simple Favor, starring Anna Kendrick and Blake Lively, and due in theaters Sept. 14.

But back in 1999, Feig and Apatow wanted to hire Jones for a series that no one was quite sure had any legs. The show was NBC's Freaks and Geeks; Sept. 25 will mark 19 years since its premiere. The hourlong dramedy revolves around a group of teens that exist on the fringes of the high school social pyramid. Jones was asked to put together an ensemble of misfits, an uncommon request in the days when television was populated by cool kids. Apatow and Feig wanted the cast to feel authentic, which meant that the actors needed to be around the same age they were playing ("They didn't want The WB network kids who were 25 playing 16," she recalls) and they couldn't look like they had ever, at any point, been a cheerleader or a jock.

Casting took place over three weeks, and Jones brought then-unknowns Seth Rogen, Busy Philipps, Linda Cardellini, Jason Segel and James Franco on board as the show's resident "freaks." Rewatch the series and you'll catch a few more familiar faces, including Rashida Jones as a high school bully and 14-year-old Shia LaBeouf, who landed a small part as the school mascot. ("He was like a Borscht Belt comedian," Jones recalls.)

Ask Jones if she had any idea that the cast would go on to become some of the biggest names in Hollywood, and she'll give you a firm "no." Well, she concedes, maybe Franco. She adds that putting together a successful ensemble like Freaks and Geeks mostly comes down to luck.

Feig thinks otherwise. Part of Jones' magic, he tells THR, is that she tracks down actors who make him completely rethink what he put down on the page. "She's really good at finding people who bring their own personality along with the character they're reading for," he says. "All you do as a writer is write versions of yourself. It takes someone with a fully fleshed-out personality to come in and make that character come alive."

When Segel walked into the audition room, for example, all long limbs, floppy hair and goofy smile, Jones knew he was the perfect fit for Nick Andopolis, the group's resident stoner/hopeless romantic. "I just remember thinking he was a big puppy dog," she says. "He was absolutely adorable and friendly and really sweet." She brought him to Feig, who was hesitant at first.

"That role was based on some guy I knew who was a different type. Physically different, attitudely different," Feig says. "In comes Jason Segel, this big, giant, handsome guy. Allison and Judd were like, he is so good, we should just adapt the role for him. We did, and thank God we did."

Jones can be a little sneaky, too. The casting director will sometimes bring Feig her first choice, only after she's shown him a few actors who aren't quite right for the part. "She's got a lot of tricks up her sleeve," he notes.

Add relentless determination to her list of attributes as well. Jones doesn't stop searching until she's found the perfect fit for the part. "A misconception about casting is that there are a million actors who can do every role," she notes. "If we're lucky, we can find one. I'm not kidding; especially in comedy."

One of the trickiest roles to nail down was Michael Scott, The Office's lovably clueless regional manager. Actors kept overthinking the part, Jones says. They brought in a lot of great comedians and it eventually came down to Steve Carell and Bob Odenkirk (Better Call Saul). Carell won out, in part, because Jones says he played the role a little "jerkier."

"When we signed Steve, I think we realized the show could be really good," says Jones, who adds, "It's not easy for a casting director to turn down Bob Odenkirk."

Finding the perfect actor is just half the equation. Next, Jones has to deal with the network. When she had exactly eight days to cast the pilot for Fresh Prince of Bel-Air, she worked around the clock to get the ensemble right. That meant fighting back against executives when they suggested the role of the British butler be played by an American actor who faked the accent (she won that battle).

Conversations can get messy, particularly when it comes to casting women who don't fit Hollywood's cookie-cutter mold of beauty. Jones will get notes from the network that they're not "excited" or "can't wrap their minds around" certain women she's brought in. Translation: that actress isn't attractive enough or a movie star.

"It drives me crazy. We've been down this road with so many women who are now leading women. Studios couldn't see it," she says. "Men can get away a lot more with looking like Seth Rogen, with all due respect to Seth Rogen."

There's much more fun and freedom when it comes to casting HBO's improvised comedy series Curb Your Enthusiasm. "Those auditions are the best," she says. "It's like seeing the show."

She brings top-notch comedians into a room with the show's star, Larry David, and then watches them go at it. There's no script for auditions and actors are just given the basic outline of a scene (for example: Larry is stuck in the doctor's office waiting room, he goes over to a nurse to complain, go from there).

"For actors who aren't afraid of improv, it's like the greatest thing," Jones says. "Larry gives 100 percent and they always end up yelling at each other."

Not everyone is enthusiastic about trying out for Curb, though. "Quite a few actors will turn [us] down because they're not comfortable with improvising," Jones says. "Especially when you have to walk into a room and improvise with Larry and Jeff Garlin. We've had some fancy names who didn't want to come in."

Going off script is much harder than it looks, she notes, and when someone is a "clunker," the whole room knows it immediately. But, if David starts laughing during the audition, Jones is pretty sure they're on the right track.

"I think going down in history, the big one was J.B. Smoove. Larry just loved him right away," she recalls. "[David] could barely make it through the audition."

Jones' voice fills with admiration when she talks about talented comedians. That appreciation might just be the key to her success, Feig says. "She's a fan," he says. "She's a fan of comedy, she's a fan of talented people and she's a fan of actors."

Oh, and her soft spot for nerds doesn't hurt, either.

"It's always my favorite when Allison calls me up and says, 'I found a real weirdo, you're going to fall in love with this person,'" Feig says. "And she's always right."