Since the late 1980s, Julia Roberts ( Runaway Bride) and her dazzling smile have brightened screens large and small worldwide. While her classic beauty quickly sealed her fate as one of America's most beloved sweethearts, the powerful chemistry she's channeled across her diverse array of film and television projects to date proves her acting prowess time and time again. Comfortable in dramas, comedies, and thrillers alike, you never know what kind of project Roberts will commit to next. You can be sure, though, that she'll dive into the role channeling confidence, charm, and authenticity.

Reportedly set to star in the upcoming Universal Pictures romantic comedy

Ticket to Paradise alongside George Clooney ( Gravity), Roberts continues her refusal to pigeonhole herself into one particular style of content. Yet, no matter the project she picks, Roberts always delivers profound strength on screen. Here are some of this Academy Award winner's most unforgettable performances over her decades-long career.

Erin Brockovich in Erin Brockovich (2000)

Julia Roberts won her Academy Award for best actress playing the title role of Erin Brockovich in this

Steven Soderbergh (Ocean's 11) film. Erin is an unemployed, single mom desperate to finally land a job and provide for her three kids. Based on a true story, Erin Brockovich tells the tale of a scrappy mom turned legal activist who plays by her own rules and follows her gut above all, waging a game-changing lawsuit against PG&E.

The charisma, determination, and compassion Roberts balances as Erin throughout this film, weaving her way through a multitude of complex relationships, is riveting. Erin musters remarkable courage, defying all odds to not only support her children but to also do right by the residents attached to her lawsuit, poisoned by PG&E's tainted water supply.

The plight of these residents suffering corporate negligence beautifully parallels the struggles Erin's faced as a single mother, trapped in an economic reality that isn't created to benefit her situation. Ultimately it's how Roberts leverages Erin's unique charms to combat obstacles as they arise that amounts to a truly exceptional, empowering, award-winning performance.

Katherine Anne Watson in Mona Lisa Smile (2003)

Set in the 1950s, Mike Newell's (Harry Potter and the Goblet of Fire)

Mona Lisa Smilesees Julia Roberts as Katherine Ann Watson, an unmarried graduate student from UCLA who takes a teaching position in the Art History department of Wellesley College, then an all-women's college. As Katherine, Roberts acts as the liberal foil to her traditionally-minded students, determined to empower as many as she can to live full lives and make use of their impressive intellects. Inevitably, scandal ensues as many of the girls refuse to be seduced by Katherine's lessons of awakening, hellbent on performing their traditional gender roles.

While Katherine does get ensconced in a secondary love story, it's the friendships she establishes with her various female students, Betty played by

Kirsten Dunst (The Power of the Dog) and Joan played by Julia Stiles (10 Things I Hate About You) in particular, that cement this performance as beautifully dynamic and powerfully feminist. By the film's end, we understand just how powerful a force female friendships can be in unearthing our collective strength and happiness.

Daisy Araújo in Mystic Pizza (1988)

Julia delights as free-spirited waitress Daisy Araújo in Donald Petrie's ( Richie Rich) Mystic Pizza. Daisy is a small town, wild child from an immigrant family inclined on having fun always.

Over the course of this story, Daisy falls for rich-kid, law school student Charles played by Adam Storke ( Highway to Hell). The pair quickly realize that the world around them is filled with apprehensive folks, unsure that a union like theirs can last.

This early performance shows one of the first examples of that raw fire Roberts regularly channels into the women she portrays. In Daisy, Roberts becomes a fiercely passionate adventure-seeker, willing to break the rules to find the happiness she knows she deserves in this lifetime.

Isabel Kelly in Stepmom (1998)

Stepmom by Chris Columbus (Home Alone) is a story about the dynamics of a relationship between two women, Jackie Harrison as played by Susan Sarandon (Thelma & Louise) and Isabel Kelly as played by Julia Roberts, the younger-woman archetype fiancé of Jackie's ex-husband Luke Harrison, as played by Ed Harris (Westworld). Soon into the story, Jackie learns that the cancer she's been silently battling has become terminal. She's reluctant to let Isabel supersede her as mother to her two kids Anna Harrison played by Jena Malone (The Hunger Games) and Ben Harrison played by Liam Aiken (Lemony Snicket's A Series of Unfortunate Events).

Over the course of the story, Isabel and Jackie negotiate their relationship, imperfectly challenging one another, and raising the question of what is the right way to be a mom?

Roberts as Isabel is this cool, big-city photographer. Her character's journey becomes about accepting responsibility, but always with authenticity. While she's not necessarily playing as much of an outcast woman as she has in, say Erin Brockovich, in Stepmom Roberts does wield her familiar strength of playing a woman empowered and committed to living life by her own rules.

Darby Shaw in The Pelican Brief (1993)

As law student Darby Shaw, Julia Roberts grounds this Alan J. Pakula (Sophie's Choice) political thriller with a quiet determination. Not long after she dives deep, thoroughly researching a paper, Darby questions whether or not her extended effort was all for nothing. She soon learns that her instincts are spot on, leading her and Denzel Washington's (Fences) character Gray Grantham down a mysterious path winding all the way up to the highest offices of the United States government.

Here, we see this same quality of determination in Roberts, a layer she regularly reaches for when painting her characters to life.

It's the heart, though, that she couples with said determination, which pulls viewers into her orbit and makes empathizing with her characters' journeys all the more effortless.

Barbara Fordham in August: Osage County (2013)

Roberts channels profound dysfunction as Barbara Fordham in John Wells's (Maid) August: Osage County. Barbara arrives back in Oklahoma with her husband Bill Fordham played by Ewan McGregor (Trainspotting) and daughter Jean Fordham played by Abigail Breslin

(Little Miss Sunshine) to support her mother Violet Weston played by Meryl Streep (Don't Look Up) and the rest of their family when their father goes missing. It's not long before we feel the inescapable brokenness of Barbara's relationships with those in her family of origin, and how those broken bonds have imprinted onto her connections with her husband and daughter.

The anger and angst Roberts channels in this role, going toe-to-toe with Meryl Streep are riveting. A profound departure from the Julia Roberts we get to see in her romantic comedies, as Barbara, Roberts unravels in a layered portrayal of the tolls of familial trauma.

Through her performance, we see a breathtaking example of unhealthy patterning and witness how beyond difficult breaking those set patterns can be.

Vivian Ward in Pretty Woman (1990)

In Garry Marshall's (Runaway Bride) modern-retelling of Pygmalion, Roberts plays Vivian Ward, a prostitute working Hollywood Boulevard the night that Edward Lewis, played by Richard Gere (Runaway Bride), needs her help driving a borrowed, manual transmission sports car. Edward hires Vivian to drive him and, charmed by Vivian, then hires her to be his girlfriend for a week as he attempts to close a pressing business deal.

Similar to her role in Erin Brockovich, Vivian is yet another example of Roberts playing a character whom those around her deem lower class. Even so, through her enrapturing charisma, Vivian manages to fundamentally shift the world view of everyone around her.

What is it that enables Roberts to so consistently win over our hearts portraying these underdog characters? Likely the unshakeable dignity she brings to each role. Roberts steps into inhabiting women like Erin and Vivian with profound respect and commitment to honoring their motivations. As a mother with Erin and a sex worker with Vivian, Roberts embodies these characters not just as heroes, but also as women, whose femininity is key to their power.