You can ask who the GOAT of LB is. I think this is not the right question to ask, and I don't think there is a single GOAT. I think there are different categories of greatness, and I think that you can be the GOAT in each category. So here is my first draft of a list of GOATs. Feel free to discuss.
Disclaimer: I am not claiming that this list is 100% accurate. In some cases I don't know enough about LB history to have an informed opinion. I am also not going to say anything about audio, just text. So if you think I am wrong or you know better, please add your input.
Achievements
Lockhart. No doubt about it. Bleu is a semi-distant second. This is the only one that can be answered pretty much objectively. See
The Greatest Of: Champions
Best Text Battler - At their best
I think DaDDiO is a reasonable nomination here. Nobody has ever dropped anything as good as Thrilla in Manilla.
Best Text Battler - At a somewhat consistent level over a long period of time
Esso. You open an Esso verse and almost every time, it's going to be an excellent verse full of haymakers. He has these complex concepts and he makes executing them look effortless. He sometimes has bad bars or lackluster verses, but not often.
Best Text Battler - Relative to the competition of their day
DaDDiO and UNKNOWN ARTIST are the only ones I can think of. But old heads might suggest someone else. Those two were active a decade and a half ago and they would at least be upper-mid tier on the modern LB.
Best Text Battler - In terms of how they influenced text battling standards
Possibly UNKNOWN ARTIST. He had his style of super clean punches in an era full of reaches and non-punches, and a lot of his bars still hold up today. I'd be interested to hear what old heads think about this. I also know some of you dumbasses would say Illokwent. Don't. Just don't. Illo is trash and always has been.
Site legacy outside battling
Part of me says X. He started the site, how could anyone else have that much legacy? The other names that come to mind are EtH, NOBLE, Student, and Mindless. Again a category where I am not qualified to name a GOAT.