I was too old by then. But i did see Theagenes fight during his prime. http://perseus.mpiwg-berlin.mpg.de/Olympics/theag.html
The more valid question would be to ask everyone which boxing events they had actually attended. I went to Valuev-Barrett, Brewster-Golota, Vargas-Castillejo, and most recently, Morales-David Diaz. All interesting experiences, all of which took place in Chicago. I remember at the Golota fight, the poles were going histerical throwing stuff at people rooting for Brewster, than they were really quiet after seeing Golota bombarded. Or the Chicago crowd not liking the Morales-Diaz decision. There was a brawl at the Vargas-Castillejo fight not too far from my seat (no, I didn't join in).
The earliest fight i attended was Tunney-Greb, their first bout. Took my camcorder aswell, i'll post it on here sometime!!!! Thought i'd join in on this!!!!!
Seriously? My great-grandmother is 105 now and she was born in 1903, making her a young adult at the time of Tunney-Greb I. Awesome if you were there, though!