Like it or not Amazon is the everything store. Damn near every single thing you can buy can be found on Amazon.
I doubt anyone can recommend an Amazon alternative, so my next question is who should I use as my "Smile" nonprofit?
Ideally it's a BASED company that won't piss money away on some bullshit.
I use my local no kill cat shelter since I got my cats there. You can try looking for local charities in your area, because the local ones don't have the recognition the big guys do, and they tend to watch their finances closely. That also returns money to your community, and that is sorely needed for many right now.
Otherwise, I would go with project Veritas or St. Jude's, or Judicial watch as others have suggested.