What motivation did Hidan, Kakuzu, Deidara, Sasori have for joining the Akatsuki? The motivations of the following characters, have been were shown in the anime:


Tobi/Madara and Zetsu wanted to capture and seal the Tailed Beasts for his Moon's Eye plan. 
Pain and Konan wanted to capture Tailed Beasts and use them to destroy the Five Shinobi Nations.
Itachi wanted to make sure the Akatsuki didn't attack Konoha or capture the Nine-Tails. 
Kisame already had connections with Madara before joining Akatsuki. 


What motivations did Hidan, Kakuzu, Deidara, Sasori, and Orochimaru have to join the Akatsuki?
As for the reasons, most of their background stories weren't clearly provided, so I am going to have make my answer with their character portrayal.


Hidan - As for why he would've joined Akatsuki, I can only surmise that it's due to his obsession to fight and kill (primarily on the aspect he was religious, he wanted to give more sacrifices to his god Jashin) and he could've seen that as bread and butter stuff of what Akatsuki was doing. He probably would've joined to work for free just for the killing.
Kakuzu - Surely money. There is no motivation other than money for him, which was shown clearly in his fight with team Asuma. That same obsession for money in fact even got him killed.
Deidara/Sasori - Their ambitions to join Akatsuki is quite vague to me. For Deidara, he was young and wanted to make a name for his art by blowing up stuffs, so Itachi challenged him to a fight, saying that if he was defeated, he would have to join Akatsuki. He probably ended up joining because of that. As for Sasori, he, being a rogue ninja like all the others, probably thought it would be safer to be along with fellow rogue ninjas.
Orochimaru - One of Orochimaru's ambition was to live for eternity to learn all the techniques. He knew the organization had stronger members and probably joined the organization to learn more about others and their skills. It's probably also because of his hate he had for Konoha.