Four-way tie; in no particular order (none of them really play anymore, either):
Jugg(ernaut) - who bribed me with Chocolate to join Geonosis. Only person to successfully get me to give up my FOREVERALONE policy.
Mace (/Kessler/Humphrey/etc.) - who took over when Jugg left and founded MogNet, and taught me how to create better character builds (even though I kept making characters with that knowledge who were better at soloing lol sorry Mace).
Cassie - who was the mistress of finding people to party with us. For a while it felt like she knew, like, everyone on the server. Much better at socializing than me.
mattz0rz - who also helped me learn how to play better, and supported me on my ridiculous side ventures to go kill crap for funsies (camped RSX and LOD for a while; never did get that ice pick) and used to keep me company doing Hugel races (STILL no ice pick). Also puts up with my constant linking of weird youtube videos.
I miss them all very much.
I still talk to Mace and mattz, but they don't play anymore.
(ETA: If anyone who used to party with us is wondering why I didn't include Mitzy in here, it's because she and I are best friends IRL, so she doesn't count for someone I met through heRO, lol.)