Ahh Vladith I think you are one of our best customers! :)

I would say your best bet for the most prestigious group of eunuchs would be the Byzantines. They had an interesting social status, as they were able to hold some of the highest positions in the court, and over time they even started invading some of the positions otherwise officially reserved for "bearded" men. They also were able to serve religious roles, and their eunuchness probably had religious implications. Eunuchs in modern Europe and Islamic societies really never had any prestige that I can argue for.

A lot of the social perceptions about eunuchs comes down to how that particular culture builds their concepts of masculinity. In early Christianity, and other cultures where celibacy can be a masculine virtue, eunuchs seem to do okay with "building" their masculinity in society as valid. So in the Byzantine era, with Christianity placing a good value on celibacy, even for non-eunuchs like monks and priests, their (implied!) celibacy was okay. In cultures where procreation is highly valued as part of what it means to be a man, they tend to do quite poorly. So, to first figure out how any society feels about eunuchs you have to figure out how they feel about men in general!

Castrati in 18 c. Europe and the Italians can be interpreted as an interesting sort of litmus test for the shifting values of masculinity at that time. John Rosselli in Singers of Italian Opera has this interesting observation that from the 1600s to the 1800s castration gradually became more shameful. In the 1600s Italians were pretty cavalier about castration, you can find straight forward records of paying for castrations in court books, letters from boys petitioning to be castrated, it's all pretty casual. But around 1700 that's gone, it's way more underground, so by the time you hit the era of Farinelli & Co, ostensibly the "heyday" of castrati, it's very shameful to have been voluntarily castrated and all these guys have little stories about falls from horses and pig attacks. Rosselli correlates this with an overall decline in the value and number of non-procreative members of society (like monks and nuns) as the European economy got better. I'd also expand this further to a shift in concepts of masculinity at that time. The book The Manly Masquerade: Masculinity, Paternity, and Castration in the Italian Renaissance by Valeria Finucci goes in to this.

Sorry this is mostly just some of my musings, nothing really historically concrete here. Let me know if I can expand on anything for you!