Wolf Guy. The (Tabata Yoshiaki) version. Now, disclaimer: in some ways, you could argue that what happened in Gal Cleaning was worse, because, objectively, the rape in Gal Cleaning was gratuitious and added nothing to the plot, whereas what happened in Wolf Guy was properly developed and a had reason to be there. That doesn't, however, change the fact that what was done to the female character in Wolf Guy was a THOUSAND TIMES WORSE and that, while in Gal Cleaning, the girl that was raped was only loose connected to the protagonist and thus the readers didn't really care about her, the girl that was raped in Wolf Guy was the heroine, the love interest of the protagonist, so, not only do we have gang rape, we also have NTR. Moreover, in Wolf Guy, the gang rape scene spanned SEVERAL chapters (admittedly, I haven't bothered to count exactly how many chapters it was, but I think there were at least eight (page-wise, I believe it's at least thrice the length of the one that happened in Gal Cleaning); it's a rape ARC, and not just a rape scene), which means readers, for months, would just get to see the continuation of one LONG rape scene. Everything is also filmed and published online, because, why not?
Therefore, from a writer's perspective, at least to me, the rape scene is Wolf Guy is a thousand times better than the one in Gal Cleaning, but as a reader, to me, it's a thousand times worse. In this instance, the reader in me wins, and, in comparison to Wolf Guy, I'd rate Gal Cleaning a solid 10.