The most members online in one day was 505, 08-12-2010.
13th Warrior, Aberration, Adran, afriestman, Agrajag, Ahellsing661, aka_hazard, AkumaKaze, albion, alemon, Alexlg89, Aliase, allan255, Amarath, Amarel, amazonwarlord, AmishLuvah, amuzani, Angus Khan, AntiZombie, ApathyProject, Atticus, AvatarForm, AWOL, Baron M, Bayou Bandit, bbb, Bellygrub, Berman, Bexley, bigstupidfighter, BitMaster, blakeh1, Blank, Bleeding Through, Borthcollective, Brandubh, Breadcrab, Brence, Breten, bringer of death, brucemanning, Brushmistress, cabal_se, Candle Jack, canudig, Cardinal Whoozey, Caronte, Catyrpelius, Celenial, Cenotaph, Chanst, chaosobscuros, Chev Chelios, Chucklemonkey, Chwineka, Ciaran, Coil, Couchmonster, cptkremmen, croth, Csonti, CubertFarnsworth, daemonkin, Daisylvzim, dakrulz55, Dance Commander, DangerousBeans, Darkcloud, DarkKoala, Dark_Trainer, darthnoir, Dax, ddot, Deadpool, Dementation, derv, Doctor Warlock, Dolomyte, dookieagain, Doomsmythe, Dr.Mercury, dragonwolf, Dragoon130, Duzzdan, dyh, Epic Jimbo, EricJ, Etna's Vassal, ExeterSquid, exileded, Exits, FacelessMage, Faithless, fildrigar, fishtank, Fivepipe, Floigl, Fook, FrankTheGodlfish, Franky, Fritz, Fulgrima, Geckilian, Genetic, Gewehr91, gnam, Gobbo, Godspeed, Gongsun, gormalesh, Gottkaiser, GreenRiveter, greenstuff_gav, gregdorf, Gremlin Swarm, Grimmwolf, gru6y, gunpowder saint, Gurslak, Guy in Suit, HamishMcGreigh, Happypanda, harbinger, Heldrak, HoAx, HopelessHeretic, HorrorJockey, huntroll, Iamwyrd, infidelx, Inquisitor Wall, Iron Man, Isawa, islyfe, ispep, Issalbotproto, izikial, JakubT, JayBarlekamp, Jedi, jereme, Jimmy Butane, Jiver, jmp_mydog, JoeB, Jolly Angus, Joona, junkenstein, Kabooomfield, Kaine, Kane, karn987, kasin666, kbdrand, KenS, Killionaire, Kilted One, KirigakurenoHaku, Koali, Kobywan, KrispyXIV, ksteptoe, Lalochezia, law and disorder, leagionair, Leb14, Leenus, Leenz, LemmingStampede, LeopolddelaSolail, Lionheart, Lnastudillo, LoboStele, Lord_Squinty, Lorenz, macgowan, Mach_5, MadArcanist, magicpockets, Magius, Magno, Major_Gilbear, Malsqueek, maple, marcuzi, MarkNorfolk, maverickman5, meechelley, mekboyz, Melnibonean, Mentor, merces, MIKEtheMERCILESS, Mister Monkey, Monkey, Monkeyclops, Mookiefer, morganclan, Mospaeda, mriverakc, mr_chuffy, MTox, MT_Nogn, Murphy'sLawyer, mythicFOX, Naexus, Natty, Navar, nerdelemental, Neverata, Neverborn403, NewbieFromHell, Nick, nick14tand, nikodamus, nilus, nimtron, Ninelives, nix, notmikehill, Nu Fenix, Nutcase168, odinsgrandson, Omadon, ork56, Ormgund, Oswald, Otaku8, pancake ss, Papa, Parintachin, Patricula, peanut, Penemue, Peoples Champ, Peterdita, Phoenix, pigi314159, Pithound, PIT_91, Placidemu, Poko, popg0estheworld, poulpox, powerslave84, powersoxette, Pox, ProdigalPunk, Prophaniti, Q'iq'el, rainborg, Raintar, rajcze, rapier1642, Rasmus, Rathnard, Raven28256, raygun, rdilgart, RedScorpionsGirl, redstripe, Rob_Jedi, RogueM, Ropetus, Rorik36, Runsamok, RuthieA, rvrchamp, SaintScythus, Sandwich, sanj, Scorpio, Scurry, scythewing, Seeker Jon, semanticdm, Sensual_Lettuce, Sephiroth, Seventeen, Sezar, sgierlinger, Shadowopal, Shinigami, simhenk, Sinistar, sirrouga, skrulnik, Skulltaker888, Slanned, Sleeper00, Sliver Chocobo, Smartah, Sobek, Souleater, Sozoa, Spacepope, squidguy, Stanislav, Stargazer, SteamPowered, stephengroy, StevO, Stomphoof, SuicideCommando, supervike, suurimonster, Svenn, tadaka, tajnisvet, Talos, Teal, tenabrae, thaehl, Thalaric, Thane, ThatTyeGuy, the good doctor, the imp, the keeper, The Madman, TheBugKing, TheCSpider, thedarkknight, theHman, themurphyfella, TheOtherChosen1, thetang22, thewartoad, Tikimonkey, TimeLapse, Tiny, Tionas, tmsmnns, tony28, Trag Sifarin, Trepstone, Triquetra, Tuesday, Tumling, tymbrimi, Uberdark, Vagrant Benthos, Veskit, Volkmair, VonPickles, vxghost, Wahahajin, warlorddawg, wedget88, Werecat, Whatsicle, Wodschow, wrabbit37, Wren, wynr, Wyrrn, XCoconutMonkey6X, yazza, Yzzuf, Zaqir, Zaxon, Zephir, Zethal, zombied00d

The most registrations in one day was 29, 05-03-2010.
Agrajag, ApathyProject, croth, Franky, odinsgrandson, Oswald, Sensual_Lettuce, Thane