Whether it was because of the result, the way the game was played or simply the teams that were facing each other (any reason why you consider it bizarre).
For me the strangest/bizarre matches were the matches between national teams and clubs:
Boca Juniors Vs. México
Bayern Vs. Netherlands
Loma Negra (Argentine Club) Vs. URSS
Atlético Socoraba (Brazilian Club) Vs. North Korea
Oceania world cup qualifying back in the day.
Australia vs American Samoa
31 - 0
Archie Thompson scored 13, nearly half his international goals.