Sometimes a marketer can show rarely seen sides of a celebrity and, in the process, create an unusual, compelling portrait. American Express has excelled at this over the years. Its latest "Are You a Cardmember?" commercial stars Tina Fey, who races around problem-solving on the set of her Emmy-winning NBC comedy, 30 Rock. "This is good stuff," she says to one writer showing her a document. "These are my divorce papers," he tells her. She flits from crisis to crisis-trying out flutes, sucking out venom ("but this is the last time!")—and even taxis home for her daughter's "octopus time." Back in the office, she receives a call from AmEx asking if she has purchased 14,000 racquetballs. She tells them no, and then is stunned to find the problem instantly solved. "I don't have to do anything?" she asks. The spot captures her wit and the offbeat management style of her onscreen persona while providing a compelling argument for enjoying the benefits of the charge card's fraud protection services.

A more personal celebrity profile is featured in a new spot for Hewlett-Packard. Branding the company as a resource for creative expression, the 30-second spot opens on pop star and fashion designer Gwen Stefani laying in bed, staring at the ceiling. "Sometimes it's so hard to find what I'm trying to say," she explains, as pictures gently float down. They then trail her as she leaves the apartment and discusses her creative process while walking around a city at night. "People think you can turn creativity on and off," she notes, as she goes on to explain that sometimes it "just comes out, a mash-up of all these things you collect in your mind." And when things fall together," she adds, "it's like magic." The spot ends with her on a balcony, looking off into the distance. The super reads, "What do you have to say?" as the voiceover prompts viewers to go to HP's Web site to find creative projects custom designed by the singer. The spot does a nice job of portraying Stefani as an artist and relaying the complexities of creativity.

Like AmEx and HP, Guinness has a reputation for producing attention-getting commercials, but its most visually stunning work usually stays overseas. Last month, an international spot aired in the U.S. It emphasizes the "Alive inside" tagline with a miniature orchestra playing inside a pint of beer. I don't want to think about what's alive in my beer, but the action-packed sequence-featuring acrobats bouncing around, hitting drums and sliding down poles representing the harp strings of the brand's logo-offers a unique take on the bubbles that rush to the frothy top. It's all about the surge. And the wait.

The thrill of the hunt anchors a new campaign for eBay that encourages viewers to "Shop victoriously," a snappier tagline than the one it replaces, "Whatever it is, you can get it on eBay." In one spot, a vintage lunchbox runs, cowers and hides from a group on a fox hunt. The spot follows the box as it hides behind foliage, ditches the pack and hides in a hollow log. Of course, it's found, but there is no death scene, just a shriek of happiness when a girl grabs it and shows off her prize. "It's better when you win it," reads the copy. The spot ends with a beaming woman sitting in her living room where she displays her find. EBay is as much about the experience as it is about its abundant inventory, and this spot entertainingly depicts the rush of excitement you feel when receiving the e-mail that says you've won. After all, who wants to be a loser?