ConraDargo
Despite being a member of the community since late 2003, the name ConraDargo may not ring a bell in everyone's ears due to his low average of posts (1.1 per day) but this member has still managed to leave a mark on the community; his most noticable work consisting of a huge compatibility list for the SNES emulators PocketSNES and SNES Advance on Game Boy Advance in 2004, where he tested more than 2000 (!) SNES roms, and a personal guide to flashing a Nintendo DS Lite which was posted in late 2006 - only days before GBAtemp's own guide went online.
The name can also be seen on numerous other forums (namely Swedish ones) and he is also the author of two FAQs: Koinu Chan no Hajimete no Osanpo for the Game Boy Advance, and the japanese version of Nintendogs on Nintendo DS - for which he has received a lot of credit.
ConraDargo is easily recognized and spotted on forums by his avatar: the two eyes which covers the cover on the popular game Flashback (The Quest for Identity).