Kind of a ridiculous title I know. Every sub-4 as a high schooler is awesome! But, of course, some are more manufactured than others (running with the pros, running against the top high-schoolers, or superb pacing). I can't speak to much about the pre-Webb sub-4s (I know Ryun's was amazing), but I would have to say the top two since Webb would be Slagowski and Verzbicas.
Slagowski did his with some pacing help through 800, but it was all him the rest of the way in a regular season high school meet.
Verzbicas was in the top high school mile in the nation, but lead most of it from the gun (I think he had some pacing too).
Both guys did it in some rainy whether too. I would probably give the edge to Slagowski personally since it seemed to come out of nowhere.
All and all, pretty sad these two still aren't in running, but I hope they have peace in their lives!