Which usernames do you recognise?
jeromec: From the viewpoint of someone pretty new:pg, of coursemechanical_fish, unalone, patio11, jacquesm, edw519, riderofgiraffes (too memorable), abyssknight. I haven't read enough to easily recognize consistently insightful commenters yet. The names I currently have in memory are there probably due to frequency, insightful comments, activity in the same threads as me, replying to me, or their name struck me as interesting/memorable.