DDNavi, the site associated with legit print media magazine Da Vinci, publishes ranks sleeveless queens
Not only is is there an otaku fetish for armpits. Not only have those people put together a ranking. They've been ranked them at DDNavi, the site associated with legit print media magazine Da Vinci.
The general assumption is that Free! would dominate a list of males, though given the torture scene, slate from Aldonoah.Zero could be a contender.
The ranking also shied away from children's anime like Precure. So, with honorable mentions given to SAOII's Sinon and Akame ga Kill!'s Esdeath, and lots of points awards for sleeveless shirts, DDNavi's top Five ladies of exposed armpits are...
5. Invaders of the Rokujyōma!?'s Sanae Higashihongan
4. Momo Kyun Sword's Onihime
3. Locodol's Mirai Nazukari
2. Encouragement of Climbl's Kaede Saitou
1. Persona 4: The Golden's Marie