Your crew members from most to least preferred, just in general (for example, who you'd pick when selecting a limited crew). You can use your own ordering system, but I've just gone with:
S Tier
A Tier
B Tier
C Tier
D Tier
Orbulon
Ashley
Mike
Dribble/Spitz
Young Cricket
Master Mantis
Red
Dr. Crygor
Jimmy T
Wario
5-Volt
Mona
Lulu
Pyoro
18-Volt
Penny
Kat/Ana
9-Volt
S Tier
A Tier
B Tier
C Tier
D Tier
Orbulon
Ashley
Mike
Dribble/Spitz
Young Cricket
Master Mantis
Red
Dr. Crygor
Jimmy T
Wario
5-Volt
Mona
Lulu
Pyoro
18-Volt
Penny
Kat/Ana
9-Volt