That Duck
I've always liked that Aflac duck. Here is an article that talks about how successful that duck has been in creating consumer awareness for Aflac. Excerpt:

Aflac, or American Family Life Assurance Co., is a multibillion-dollar purveyor of supplemental workplace insurance with a 49-year history. But few people had ever heard of the Columbus, Ga., company until four years ago, when the duck arrived. Since then, Aflac's sales have increased by 20 percent, and its "consumer awareness" shot to 90 percent from 12 percent. The duck's "Aflac!" quack is part of the vernacular, and toys and T-shirts abound.

What's notable, though, is that Aflac did this on the cheap. Creating a brand icon often takes years and can require a massive ad budget. Aflac spends only $45 million on commercial time annually, a relatively paltry sum in the ad business.

By contrast, a significant portion of McDonald's Corp.'s $680 million annual ad budget supports Ronald McDonald, who has a lower Q score, the measurement marketers use to rate a character's familiarity and appeal. Energizer Holdings Inc. has lavished about $1 billion on its veteran Energizer Bunny over the past 15 years, also with lower Q results.

Met-Life sort of had the same thing when they used the Peanuts characters for their commercials. Another relatively boring financial services company that got brand recognition through catchy marketing.