There was a great ad a few years ago on the Philly CL. A guy had an old beater and the title of the ad was "BEST BIKE IN THE WORLD!".
The first photo was of the bike, the second photo was of a little girl and a man standing against a wall frowning and looking very sad, the third photo was of the little girl riding the bike with a huge smile on her face while the man, also grinning like a maniac, was pushing her on the bike, and the fourth photo was of the man on the bike while the little girl pushed him, both smiling of course. The text of the ad was something like: "This bike will magically cheer you up!".
I am sure it got a lot of great responses and he probably sold it for the asking price.