The first is obviously Lisa Silentland. She is on Cupcake Valley, UK server, and she was my first account and I use her for my main SSO play, including questing, talking with my club and more.
My next account is Christina Moonpeak. I made her to help me learn Swedish and she lives on Air Star, the first Swedish server. She doesn't get used as much as I'd like due to IRL.
I felt very left out when some of my mates started hanging about on the NA servers so I made Meja Season. She is on Frost Valley, although I want her on Night Star when it opens. She's just there for social stuff I guess!
Chiara Summerlund chills on Spring Star because I got bored and wanted something to do. So she sits there having fun and lets me practice Finnish... Ok, I can't speak Finnish.
Maybe my most useful account is Zoe Macer who is on Blueberry Mountain. I use her for learning French which I think really helps me!