About 100,000 of us going nuts for the Indomitable Lions that day, everyone loves an underdog. Cameroon 0-2 down at half time, equalised late in the second half, had two seemingly perfect ‘golden goals’ disallowed in extra time, then won in the shoot out. Amazing game, and a once-in-a-lifetime experience.
The actual attendance for the 1970 Grand Final was technically 121,697, as The Devil Himself was also present at the MCG that day (according to Pie fans). However, metaphysical beings who don't need to pay for admission are not counted for the purposes of the 'official' attendance.*
(*This has been standard practice for ground managers since 1897.)
Therefore, applying this same methodology, the biggest AFL crowd that I have been a part of was the 2008 GF, where the actual attendance was 100,013 (fittingly, the devil's number).