Sky One's Dream Team had a few alternate football scenarios.
S1: 1997-98: Harchester are shown beating Arsenal 2-0 in the FA Cup, meaning no league and cup double for Arsene Wenger.
S2: 1998-99: Harchester win the FA Cup, so no English club has won the treble yet. More importantly, a player being assassinated by a sniper at Wembley would have massive implications.
S3: 1999-00: The final day of the season sees Harchester and Bradford (who stayed up IOTL) fighting for safety. (An unofficial website handwaved it by mentioning Wimbledon losing at Everton)
S6: 2002-03: The bottom four are Harchester, Bolton, West Brom and West Ham, rather than Sunderland. In addition, Harchester are told 2-3 days before the FA Cup Final that they can play either their final league game (which they need to win to stay up) or the Cup Final. I wonder how Chelsea (the side they beat in the semis) got all the cup final tickets on sale and sent out in three days...
S7: 2003-04: The consequences of a Premiership side nearly being folded in mid-season at the same time that Leeds were imploding would likely lead to the FA implementing strict ownership rules and probably averting the demise of Portsmouth. In addition, Harchester finish fourth ahead of Liverpool and Newcastle, so Istanbul doesn't happen.
S8: 2004-05: With Barcelona winning their CL group, the bad-tempered R16 tie against Chelsea doesn't happen. Arsenal are shown to beat Harchester in the quarter-final, my headcanon is that the semifinals saw Arsenal face Barca and Milan face Chelsea, with Milan beating Barca in the final. The biggest butterfly, however, is caused by the ex-manager driving his car into the team coach after the playoff final, blowing it up and killing himself along with much of the team. Presumably, this would lead to MASSIVE changes in stadium security.