Simply put, Willie Freakin' Stargell.
As a kid growing up in Illinois in the 70's, the Cubs stunk and I lived nowhere near Chicago. We did, however get the Cubs games on WGN. I became a Bucs fan the instant I saw Stargell wheel that bat around and hammer home runs out of the park. Dave Parker came shortly thereafter and was a thrill to watch as well. I was hooked and have been a fan ever since. Watching the Bucs come back from 3-1 in the '79 WS was a big thrill!
I live in FL now and make the trip to Bradenton every spring.