Surprised there hasn't been a thread for this already but here goes...
Has to be Kick Off 2 on the Amiga for me, not exactly for the realism but purely for the speed, playability and skill required to master the bloody thing. A lot of people would go for sensible soccer from that era but, for me, that game was just for people that weren't skillful enough to play KO2. Plus you had the added bonus of being able to score from the halfway line and being able to get half of your team sent off if you had a card-happy ref....good times!!
Maybe I'm showing my age here (bah!) but must say that the pro-evo's and fifa's of this world pale in comparison! in playability terms that is....