A feel-bad romantic comedy that should have been a straight drama, "The Break-Up" puts an unorthodox spin on the genre by being about the end of a relationship rather than the start of one. Not as ruthless as 1989's "The War of the Roses" and also, thankfully, not as bleak and cold-hearted, the film nonetheless stays true to its title as it develops a mostly realistic and knowledgeable portrayal of a love gone sour. Misleadingly marketed as a silly little romp in its trailers and television ads, director Peyton Reed goes for a more serious tone much of the time that serves the material well. Attempts at bawdy humor straight out of a sketch comedy are out of place, and worse, not particularly funny. What surrounds these failed interludes, however, is sad and poignant, the pain that comes with these characters' difficult situation cutting directly to the bone.

Chicago tour bus guide Gary (Vince Vaughn) and art gallery assistant Brooke (Jennifer Aniston) meet one day at Wrigley Field and quickly come to believe they've found their soul mate. Switch forward a few years, the couple's relationship has noticeably dimmed, with Brooke feeling underappreciated and Gary feeling smothered. A big fight in which their pent-up resentments and ill emotions are released ultimately leads to a break-up. With Brooke holding out hope that Gary will see the error of his ways and Gary too pessimistic to realize Brooke is hoping for a reconciliation, they continue to live under the same roof—a living arrangement destined to create bigger problems than they already have.

"The Break-Up" is an uneven star vehicle for Vince Vaughn (2005's "Wedding Crashers") and Jennifer Aniston (2005's "Rumor Has It...") that, under the pen of first-time screenwriters Jeremy Garelick and Jay Lavender, tries too hard for laughs that rarely see liftoff. This is especially true of the film's second act, which awkwardly tries to make light of the ex-couple's bickering and their attempts to make each other jealous.

It is also true of the misuse of a fantastic supporting cast, few of them given much to do but be a sounding board for Brooke's and Gary's problems—respective best friends Addie and Johnny O, played by Joey Lauren Adams (1999's "Big Daddy") and Jon Favreau (2003's "Something's Gotta Give")—or fall into flat stereotypes—Brooke's effeminate brother Richard, the head member of a men's a cappella group (John Michael Higgins), and Brooke's effeminate (again) coworker Christopher, played by Justin Long (2005's "Herbie: Fully Loaded"). Of the supporting cast, only Judy Davis (1998's "Celebrity"), as gallery owner Marilyn Dean, stands out as she is refreshingly revealed to have far more going on beneath her steely, high-strung surface than meets the eye. As for the remaining male characters, they are unfavorably depicted as louts, pushovers, or womanizers, which is especially surprising considering two men wrote the screenplay and must see themselves as such.

This unfortunately carries over to co-protagonist Gary, who is more obnoxious than likable even in the opening scene where he is supposedly wooing Brooke for the first time. Gradually, Gary grows as a person and experiences a life-changing epiphany about his own selfishness, redeeming himself enough that he finally becomes sympathetic. This personal discovery doesn't arrive until near the climax though, which leaves a lot of screen time where he is simply insufferable to be around. Every step of the way the viewer is on Brooke's side; she is, after all, valid in her unhappiness with where their relationship has gone, and tries mightily—but to no avail—to make Gary understand what she is feeling.

If "The Break-Up" is riddled with tonal schizophrenia and some problematic character sketches, what it is not is dishonest at its core. For all of its comedic nosedives, the film is frank and uncompromising as a study of the final weeks of a relationship. Most adult viewers will be able to relate to Brooke and Gary, or at least to the experiences they face once they have broken up. Their anger, their denial, their heartbreak, Brooke's false sense of hope that maybe they can work things out—it's all laid out by director Peyton Reed with bitter truth and genuinely touching pathos. As for two particular heated confrontations—one leading up to the break-up and another late in the picture where Brooke's vulnerability gets the best of her—they are so perfectly acted and dead-serious in their candidness that it becomes uncomfortable in the most appropriate way, as if the viewer is eavesdropping on an actual couple's unraveling seams.

After a string of mediocre post-"Friends" film roles (2005's "Derailed" and "Rumor Has It..." among them), Jennifer Aniston finally comes into her own and finds a presence and voice she hasn't had since her Oscar-worthy turn in 2002's "The Good Girl." Brooke is the heart and soul of "The Break-Up"—indeed, it is she who we care the most about and identify with—and Aniston is both luminous and deeply moving in the role. As Gary, Vince Vaughn has a more difficult time because his character is so daft in accepting his mistakes. What these two actors do collectively succeed at is in finding the nuances and believability of a real couple.

"The Break-Up" ends on an unexpected note that may not please the unashamed romantics in the audience, but develops naturally and authentically. It may not fall within the boundaries of a mainstream "happily-ever-after" conclusion, but is satisfying and cathartic and somehow upbeat all the same. Director Peyton Reed puts just the right finishing touch on a film that, like any long-lasting relationship, has a fair share of bumps and bruises. As a comedy, the story is too sobering and the jokes too limp to tickle the viewer's funny bone. As a relationship slice-of-life, "The Break-Up" is more comfortable and in its element. On this level, the movie holds a maturity and wisdom reminiscent of an early Woody Allen.