I would say that one of the most effective ads of any company that I have ever seen comes from Apple. They are geniuses when it comes to any of their advertising campaigns. Let me offer a few examples.
In the 1995 they started an advertising campaign about being creative. It was their "Think Differently" campaign. This created a market among creative people and educators. What Apple did specifically was to focus on people in history that they believed thought about the world in a different way. In their one minute commercial, they had pictures of people like Martin Luther King Jr., John Lennon, Bob Dylan, Ted Turner, Albert Einstein, and many other people. In this way, Apple was able to take the influence of such people and grafted it onto their brand.
Another very successful campaign was the "Switch to Apple" advertisement. Their commercials were very simple. One actor played a PC computer and the other actor played an Apple computer. Needless to say that actor who represented Apple took jabs at the PC. It was all in good humor, but it did send out a message that Apple computers were better.
In terms of effectiveness, Apple is one of the richest companies of the world. This says it all.