Comedies involving teenagers usually fall into one of two categories: those that want to shock, appall, or gross out with their R-rated bawdiness, and safer PG-13 items that usually involve some kind of bet or game or transformation that leads to two people falling in and out and back into love. Both are perfectly respectable in their own right, but they are also variations on the same well-played, cookie-cutter mentality. How "Nick and Norah's Infinite Playlist" ends is easy to guess, but one of the purveying reasons why the film transcends its genre is because it breaks the mold and doesn't fall into easy traps. If the plot trajectory strikes familiar notes, it also is gloriously restrained in its treatment of characters who are so immensely real, watchable, and charismatic that the 90-minute running time could have easily been doubled without any strain. That the title protagonists are still in high school is beside the point; theirs is a romance, like the ones in 1995's "Before Sunrise" and 1999's "Trick," that nails exactly what it is like to fall in love, no matter age, gender, race or sexual preference. Ways of the heart are universal.

Ever since girlfriend-of-six-months Tris (Alexis Dziena) unceremoniously dumped him on his b-day, Nick (Michael Cera) has been unable to get over the break-up, the series of mix CDs he's made her falling on deaf ears. Straight-edged Nora (Kat Dennings), who goes to school with Tris, is a different story; she has never met Nick, but has fallen in love with one of his self-made song compilations. When Nick and Norah separately head into New York City on a Friday night, they find themselves at the same club, he to play a gig with his queercore band The Jerk-Offs, and she to let loose with boozy friend Caroline (Ari Graynor). When Tris shows up and taunts Norah about her single life, Norah retorts by choosing Nick and asking him to pose as her boyfriend for a few minutes. She doesn't yet know he's the same person that she has felt a connection with through his musical playlist, but soon will as they join forces and venture into the night to find a barely-conscious AWOL Caroline and locate their favorite band Where's Fluffy?, set to perform at a top-secret location.

"Nick and Norah's Infinite Playlist" cares about its characters and really listens to them. Their actions are not dictated by Lorene Scafaria's screenplay (based on the novel by Rachel Cohn and David Levithan), but by their natural personalities. They also have more going on upstairs than thoughts of the here and now, grappling with issues destined to impact their futures (i.e. Norah isn't sure whether or not she wants to go to college at Brown, and has until the morning to give the school her answer). In building the foundation for Nick and Norah's romantic fireworks and simultaneous overnight adventure, there are no flimsy misunderstandings or contrived crises, the cursory conflicts instead arising from things that might potentially occur for a group of teens let loose in the city. When Tris gets jealous and shows back up to reclaim Nick, he chooses to leave with her over Norah (for the time being) out of dedication and responsibility, but obviously has warring feelings inside. And, while on the zany side, Caroline's drunken, hilarious, events-filled trek through Manhattan is just grounded enough to be plausible.

In mounting the project, director Peter Sollett (2003's "Raising Victor Vargas") has done a stellar job with material that could have easily become over-the-top or frenetic. His weaving of the ensemble—not only Nick and Nora, but also Caroline, Tris, Nick's band members and friends Thom (Aaron Yoo) and Dev (Rafi Gavron), and the colorfully nicknamed Beefy Guy (Jonathan B. Wright)—throughout the course of the narrative is like a fine tapestry, given an added boost by pacing that knows when to be light and fast and when to slow down and concentrate on developing the cornerstone relationship. Stereotypes are left at the door, too; the closest thing to a villain is really just an insecure girl herself, while three gay characters, Thom (Aaron Yoo), Dev (Rafi Gavron) and Beefy Guy, are treated with a rare respect, acceptance and normalcy that makes one rue how dumbed-down and irresponsible most studio-bred comedies are on the subject.

Laughs are plentiful—Ari Graynor (2006's "For Your Consideration") is comic dynamite as Norah's hopelessly lost zonked-out pal Caroline, and the dialogue is witty without being showy—but the film's soul lies in the innocence and sweetness of Nick and Norah's budding feelings for one another. With the pulsating, diversified nightlife of New York City coming alive through Tom Richmond's (2007's "The Ex") twinkling cinematography, these two characters finally get to spend quality one-on-one time together as dawn approaches. As purely fun as the opening hour is, the third act is simply enchanting. The emotional honesty and level of satisfaction that comes with the final scenes are palpably realized.

Michael Cera (2007's "Superbad") has not yet proven his range as an actor—his leading-man role as Nick is a step in the right direction, though—but is there a more unassumingly adorable performer working in film today? There doesn't appear to be a cruel bone in his body, which makes the viewer want to root for his happiness all the more. As Norah, Kat Dennings (2008's "The House Bunny") is endlessly appealing, emanating goodness but not perfection. Neither Nick nor Norah have the world figured out—do any of us, ever?—and it is in that area of vulnerability that they prove to be an ideal, sympathetic couple with potent chemistry. When Cera and Dennings share the screen, magic takes place. The game supporting performance from Alexis Dziena (2008's "Fool's Gold"), as Tris, is also worth noting. Dziena could have tackled this character as an airheaded sexpot, but she plays it in a lower key. Yes, she is self-absorbed and catty, but she's not above having feelings and regrets of her own.

For a film that advertises within the title a propensity for music, "Nick and Norah's Infinite Playlist" does not disappoint. The wall-to-wall soundtrack could have afforded a few more older, recognizable tracks, but every song choice (by up-and-coming artists such as Vampire Weekend, Bishop Allen, Shout Out Louds, and Band of Horses) is nevertheless flawlessly integrated into the scenes and compliments the characters' personal tastes. Like a movie that '80s-era John Hughes never made, "Nick and Norah's Infinite Playlist" is candid, thoughtful, touching and hugely entertaining. By never talking down to the characters or the audience, it should endure as a teenage romantic comedy staple, loved and identified with by those old enough to remember when it was released and future generations not born yet. Lofty accolades, indeed, but deserving of them.