I am trying my best to not buy them all. Thankfully the shortages for 3 of them have made it easy, so I'm just going to have ones for characters I like most from franchises I care about or ones that work in multiple games that I'll buy.
So far:
Mario, Donkey Kong, Link, Pikachu, Samus, Fox, Yoshi
Pre-ordered for next week:
Captain Falcon, Family getting me Luigi and Diddy Kong for Christmas
Wave 3 Pre-Orders:
Lucario, Toon Link, Bowser, maybe Sonic
I never cared for Fire Emblem or Kirby games really and don't really care enough about Peach, Rosalina etc. to get them
I also intend to get, whenever they come out
Bowser Jr., Duck Hunt Duo, Charizard, Greninja, Jigglypuff, Ganondorf, Wario, Falco, maybe ROB
My poor wallet. If they ever do Pokémon focused amiibo, I'm screwed.
I'll also buy a Captain Toad amiibo at the drop of the hat should it come.