On That '70s Show, sassy Donna Pinciotti was one of the most likable, relatable characters. The wise-cracking yet goodhearted neighbor, played by Laura Prepon, was smart, funny and adept at handling (and rolling her eyes at) her totally insane parents.

It's possible that I transferred some of my goodwill towards the character to the actress who played her. At the time, Prepon (to me, at least) seemed the most likely of the cast to go on to bigger and better things. After all, she was both striking and down-to-earth, with a rich throaty voice and beautiful red hair that set her apart from all of the other actresses out there at the time.

Of course, that hasn't proven to be true. Jackie and Kelso (Mila Kunis and Ashton Kutcher) have gone on to become the biggest stars, eclipsing all of the others by far. While Kutcher never really left the spotlight, Kunis' star has risen recently with big hits like Forgetting Sarah Marshall, Friends With Benefits and Ted. Eric (Topher Grace) has been working steadily, and appears to have made a successful transition from TV to the big screen with big titles like Spider-Man 3 on his resume.

Hyde (Danny Masterson) has also been working regularly, and recently landed a starring role on the new TV show Men at Work. Even Fez (Wilmer Valderrama) has enjoyed a prosperous career, with bit roles in movies and a fruitful gig as the voice of Manny on the popular kids' show Handy Manny.

With the exception of train wreck/frequently incarcerated Lisa Robin Kelly, who played Eric's evil sister Laurie on the show, Prepon has gone on to become the least successful cast member, and not for lack of trying. She hasn't intentionally disappeared from the limelight to pursue a college degree or quietly raise a family.

No, she's been toiling away for years, giving the whole acting thing a go. She even took on the incredibly controversial role of reviled serial killer Karla Homolka in the 2006 flick Karla. While the film itself sparked outrage, it didn't translate into extra attention for poor Prepon. Things started looking up when she landed the lead role on the NBC series Are You There, Chelsea?, based on the bestseller by Chelsea Handler. But the sitcom was universally panned and quickly cancelled, and, less than a year later most people have probably already forgotten about it.

Once again it seemed like Prepon finally caught a break when she was cast in the latest Stephen Frears flick, Lay the Favorite, opening in select cities this week. It co-stars big names like Bruce Willis, Catherine Zeta-Jones and Rebecca Hall. Unfortunately, appearing opposite talent like that only highlights Prepon's weaknesses as an actress.

While Hall (who is British, by the way) is perfect as a ditzy mid-western sweetheart, American Prepon can't even nail down her character's subtle southern drawl. She seems to be focusing so hard on getting the accent right that she forgets to act. As Hall effortlessly emotes and makes us feel for her, Prepon delivers her lines in a ridiculous, over-the-top manner.

To top things off, Prepon has a topless scene that seems completely unnecessary, and even that didn't generate much extra attention for her. (Lay the Favorite was released in other countries earlier this year). She's trying every trick in the book to generate buzz, from tackling controversial roles to taking her top off, but nothing seems to be working for her. She's even a Scientologist! Say what you will about the Church of Scientology, it has produced a lot of famous actors. (Tom Cruise, John Travolta, Kirstie Alley, Jason Lee and Juliette Lewis, to name a handful.) The Hollywood networking opportunities she gets through Scientology may explain why she keeps getting cast in stuff despite her many public failures.

So what should Prepon do? I think dying her hair red again would be a good start. Hollywood has enough blondes. As for getting more ink, she should rip a page out of Wilmer Valderrama's book and start dating celebs who are more famous than her. Even better, she should be the one who comes between current lovebirds Kutcher and Kunis. If that doesn't land her some tabloid covers, I don't know what will.

Loading Slideshow

• Ygritte, "Game Of Thrones"

• Joan Harris, "Mad Men"

• Mitchell Pritchett, "Modern Family"

• Amy Pond, "Doctor Who"

• Emma Pilsbury, "Glee"

• Nicholas Brody, "Homeland"

• Tessa Altman, "Suburgatory"

• Arlene Fowler, "True Blood"

• Horatio Caine, "CSI: Miami"

• Lily Aldrin, "How I Met Your Mother"

• Kathy Griffin, "Kathy"

• Owen Hunt, "Grey's Anatomy"

• Julia Houston, "Smash"

• Meredith Palmer, "The Office"

• Conan O'Brien, "Conan"

• Addison Montgomery, "Private Practice"

• Lois Griffin, "Family Guy"

• Bree Van de Kamp, "Desperate Housewives"

• Evelyn Harper, "Two and a Half Men"