It's nothing that's not easilly found on FFG's website's product description...
But here we go:
Original Core Set: Joe and Sigrid.
Revised Core Set: Rhino and Lara.
Operation Cyclone: Rosie and Manfred.
Operation SeeLöwe: Ozz 177 and Markus.
Operation Cerberus: The "chef" and Angela.
Operation Zverograd: Koshka and Gran'ma walker (not yet listed in Dust Warfare).
"Official" promotional material not available anywhere now: Loth walker.