I'll vote for @Exoticz as well for his activity in discord especially the help section and generally being a chill/friendly guy.
Honourable mentions: @Juws ,@Zora ,@Devil, @Chich
I have done a lot of business with Zora and could easily leave him several vouches for our transactions. Vouches are usually a formality and having done business with nearly all of the big traders on Sythe I can still say he is easily one of the best traders on Sythe. I would have no hesitation...