Oh, yes, I most certainly agree. As a matter of fact, I have a whole encyclopedia based upon Demons and Demonology. It's rather... interesting, actually. Why, I just love slaving over that book and filling my mind with all of their information. Some of my favorites include, but are certainly not limited to: Andras, Amon, Baphomet, Beelzebub, Leviathan, Marchosias, Phenex, the Succubi, and Zozo. They're *all* rather... engrossing, however. They've even managed to carve a little place within my heart, those demons. After all, they're quite enticing creatures and, believe it or not, not even all of them are evil... Take Amon, Marchosias, and Phenex, for example. None of those are particularly... evil demons.
Amon: Amon is a demon who can see both past and future; settles disputes between both friends and enemies; and can help those who seek it, find love.
Phenex: He's actually a rather peaceful demon - one who sings incredibly nicely (supposedly like a sweet child) and wants to go back to heaven after 1,200 years, but is always deceived in his own hope. Upon shifting into his human form, he'll tell those who have summoned him of "great sciences" (he's very obedient to his summoners, too). He's also a wonderful poet, they say.
Marchosias: Though an incredibly strong demon, he speaks the honest truth and is very loyal to his summoner(s) (like Phenex is). Also like Phenex, he, too, wishes to return to heaven in 1,200 years. However, he is also deceived in his own hope.
As for the other demons, they're all different stories, though you should have heard of most. After all, Baphomet, Beelzebub, Leviathan, and the Succubi species are all rather popular demons. Same with Zozo, but really only if you have a particular interest in Ouija. Besides, the Zozo demon is has a particular correlation with Ouija boards... Now, isn't that interesting?
I could go on all day about Demons and Demonology, but I won't waste your time. However, if you do yearn for more information regarding such wondrous creatures, feel free to reach out to me, dear. I'm always up to sharing my knowledge on my beloved little monsters.