Seahawks bandwagon is really really big right now but they did build it up from the Hasselback/Alexander days, which was from 10 years ago. Prior to that they were nonexistant. There were prob a few Brian Bosworth fans but that was about it.
I actually remember the '97, '98 Heat a little bit. Nobody thought they were a threat at all to the Bulls. Nobody really cared about them besides Knick fans. 15 years later they became the most hated team in the NBA.