From my perspective, the only choice is Homerun Throwback. It was the perfect storm. Not only did we get back-doored by the officials, but it was the whole Rob lost/Flutie was screwed intertwined.
To put numbers on it (remember this was back in 1999), on really, really active days we would get 600 messages posted (small by today's standards). On that day, we had 1200 in a few hours before we were turned off. I estimated it would have been about a 2000 message day. I got hate mail because I did not lease multiple servers and setup a distributive computing cluster for one playoff game (considering the perl code I was running it would have taken that much).
The day Johnson was announced over Flutie was large too. That was in the dark days of Rivals.com. Even with that piss-poor operation, we managed to get 250,000 page views in one day (I can only imagine what it would have been if the boards were responsive). That was 5x the normal traffic back then.