Basing it on looks it goes like this:

S1: Ophelia Lincoln.

S2: Veronica Blade.

S3: Anya Ivanova.

S4: Giulietta Capecchi.

S5: I would say either Juniper or Meera Kat. Can't decide between the two.

S6: Nefertiti or Simone Severine. Again can't decide.

S7: Rubarae.

S8: Noemie Leprince.

Shawna Knox, Asal Hawaa, Annabel Stewart, Aurora Dawson, Lola Dickinson, Olive Powell and Monday.

Interesting question... okay.

Season 1: Madison Springer

Season 2: Heather Valentine, Amy Young and Jenny Galguera... Wait...

Season 3: Asal Hawaa, Anya Ivanova and Nomena Leroy

Season 4: Giulietta Capecchi

Season 5: Cindy McMinn, Sally Hooper, Monica Pozie and Sam De Witt (I know Sam was a hated person but come on, she's pretty)

Season 6: Nefertiti and Teresa Martinez

Season 7: Rubarae

Season 8: Eleonora Macaron and Ava de Paradis

there's a lot... but what comes into my mind right now is Celine Georges & Sergei Yablokov.

Rita Estavez. i have more but i think some of the protagonist's companions are quite hot.

For me its the one and only Cathy Turner

Uhm for me is Doctor Jennifer Russo and Polly O'Brien

Also, Minnie Starr.

Jack Archer, no contest.

S1: Ophelia Lincoln, Ramona Stewart and Elvira Milton.

S2: Lucy Armstrong, Astrid Saucer, Eva Grant, Abbi Absinthe and Heather Valentine.

S3: Anya Ivanova, Veronica Salter and Christy Mathis.

S4: Giulietta Capecchi and Eliza Rheinberg.

S5: Daisy Woods, Chelsea Bloom

S6: Nefertiti or Tamat Loren.

S7: Rubarae.

S8: I can't think sorry