I’m usually rockin’ Original 4, but I love Alt 2 as well… probably because of the hat, lol.
Original - 4, 9, and 10.
Alt 2 - Black (forgot which number), 10
Alt 3 - 4, 7
Least favorite?
Original: 9 (sickly green with orange scarf)
Alt 1: 5 (red with ugly yellow scarf)
Alt 2: 9 (black and pink with gold scarf)
Alt 3: 2 (yellow with orange scarf) or maybe 6 (cream with orange scarf)
I don’t think I have a least favorite. Probably any of the colors I didnt list, I guess. :-p
I’m not as fond of alt 3 as I thought I would be, though.
Alt 2 - 6
Alt 2 - Color 10
07 regular cosutme, blue with the white scarf and yellow buttons
Original, 4 or 10.
At this point, I’ve been using pink and blue a lot more than usual. (Original).
Stupid stations don’t have pot monster costumes :(.
Burlesque Rose for me - fighting Cowboy Ken makes the game feel like Super Street Fighter IV: Deadwood Edition 1812…
Alt 3 Color 9 ,“Black” looks like a shinigami 
Alt 1 color 8 (her gypsy fit with white and grey.) And her blue original fit. Not a big fan of her huge dresses.
Original 9, as someone said a few posts ago ‘sickly green with orange scarf’
It’s the only colour I really liked and stood out for me, everything else of the original just looks the same.
Does the Femme Fatales pack give you all of the alternates…Steam?
Original 8 but I like original 4 as well. I dislike all her alternate costumes.
I mostly use OG #10
But if i feel like dressing up, i wear the black or peach wedding dress.
I use alt #3, Tan (color #5 or #6 I think).
Alt 3 with purple. she’s like a high class burlesque dancer
My main pick would have to be original #8, the beige colour.
Occasionally I would choose #7 or #10, but my main is #8.
As for Alts, the only, one I really like is the second one, the other two just do not flatter her. And I have yet to purchase any of the recently released costumes.
So for that one I’d normally go with Alt 2 and colour #7