Sasha. As much as I love Charlotte, she's the one of the two who's confirmed mega ticklish. Sasha has inferred it but not outright confirmation.
Jennifer Lawrence vs Saoirse Ronan
A fun little article from UK presenter Kate Garraway. Highlights for me:
"On Day Five, I discovered I like tickling.
On Day Six, I discovered he didn’t."
https://www.telegraph.co.uk/women/sex/kate-garraway-saved-love-life-14-day-sex-binge/
I'm straight and into tickling, I let a friend of mine who isn't straight and wasn't into tickling tie me down naked. It was wild. I ended up begging and cumming, then begging again.