MAB 1 springs to mind but I haven't actually watched it since around the time it happened so it could just be the nostalgia effect.
The Barrera 1 fight was the first time I saw Pac, it happened to be on tv in the pub and I couldn't believe the ferocity of this little dude ass whooping the guy that schooled Hamed. After that fight I've followed his career since. He's had a truly amazing career. The Cotto fight was awesome too destroying a very good boxer in a big weight class.