I think a lot of people from the PC client had their moment of a few months where they were #1
I can recall Neo and Deo winning many of the earlier competitive UTCs, then Brett and Quick Strike started winning a bunch, then I think Ares and I had a run where we won many of them around the same time period

I don't really know what happened after that because I quit somewhere between 2008-2009, but Ares and Brett probably won a lot more
Neo won a bunch all in between there and I forget when or how many Highlander won

UTC was the important one but Babylon and Delteria had really good tournaments as well, those Delterian MV and Insomniac tournaments were cool
The scrub era must have began afterwards because the only circumstance where I can imagine Warhawk or Sean being considered at the top is if everyone else quit, so I'm just gonna invalidate that entire time period and pretend it never happened

David, Jack, Prado, and Zeross are good and from that same generation of sparrers though
I still think Brett was the best when it mattered most because he'd pretty regularly crush every other good sparrer, specifically when he was using the "Holy Knight" account since that's when I think sparring was probably the most competitive

It's all obviously an opinion but I think stuff like this can be validated based on tournament performances and spar records, but some wins just don't mean as much before or after certain time periods because sparring was just dry