Consensus was that Michael Jordan decisions Shaquille O' Neal over 12 rounds of table tennis, but only on clay, at a catchweight of 250lbs.
I've just been on the skiing forum, and asked them to compare the attributes of Ronnie O'Sullivan & Tiger Woods, and which would be favoured in a H2H triathlon made up of frisbee, pumpkin carving and goldfish - rearing. When I get the results I'll post them here and we'll all be that bit closer to deciding whether Monzon or Hagler was better.