Canon Friends (out of game, all of them :( )
Jason Lee Scott
Trini Kwan
Zack Taylor
Kimberly Hart
Tommy Oliver
Rocky DeSantos
Aisha Campbell
Adam Park

IC Friends
Renne
Katara
Jamie McCrimmon
Kaylee Frye
Wyn Callahan
Kang
Goliath
Allen Gentry

IC Acquaintances (oh god we'll be here all night)
Tenaya
Fifth Doctor
Tenth Doctor
Irma
Sensor
Sasami
Arha
Jono
Brainy
Paco
Stephen
Nanashi
Lash
Ax
Kira
Yzak
Pyro
Daimon
Every engineer who isn't already a friend

Stopping here because I don't want to list half the game. And then I'll find out I missed someone important, right?