Which usernames do you recognise?
nostrademons: The question is inaccurate, because you're really asking which usernames we can recall. ;-) That's often an order of magnitude smaller than the ones we can recognize.  The only way to test who we recognize is to MRI us, show us a bunch of usernames, see if the recognition centers of our brain light up.That said, here's who I can recall off the top of my head:YCombinator principals: pg, rtm, jl, tlbFamous people: joshu, pmarca, paul, jeresigSemi-famous people: aboodman, tptacek, cperciva, lisper, jrockway, ojbyrne, epi0BauquYCombinator founders: sama, dhouston, ivankirigin, tipjoy, spez, aaronsw, mattmaroon, AlexS, SwellJoe, brezina, fallentimes, brett (at least, I think it's that Brett...the SlinkSet founder)YCombinator company employees I've hung out with or otherwise interacted with: aston, dfranke, gaborcsalleFolks I've met in person since moving to the Bay Area: lacker, litewulf, iamelgringo, abossy, timcederman, gaiusProlific posters: nickb, rms, wheels, davidw, mechanical_fish, DanielBMarkham, edw519, swombat, patio11, raganwald, pchristensen, staunch, byrneseyeview, llimllib, ryanwaggoner, Alex3917, menloparkbum, DaniFong, dcurtis, unalone, masklinn, apotheon, plinkplonk, mynameishere.(Yeah, I cheated and looked at the leaderboard and a few comment threads for that last one.  The original question was recognition, not recall though.)