John Madden Football for the PC in '89.
http://en.wikipedia.org/wiki/John_Ma...all_%281988%29
Then Tecmo Bowl for NES in '89.
I spent hundreds to thousands of hours playing these games. On the PC I edited rosters, drew up plays, created my own schedules, kept track of my own stats. It was great.
I then got into the Front Page Sports series in '92 and went online with that a few years later. And I haven't stopped playing online since. Now it's BBCF, FOF, and OOTP.