Off the top of my head, here are a few non-profits in the US:

Internet Society / Internet Engineering Task Force

The Electronic Frontier Foundation

The Free Software Foundation

The Linux Kernel Organization

Southern Poverty Law Center

NAACP - 501(c)(4)

Planned Parenthood Federation of America

Corporation for Public Broadcasting

MacArthur Foundation

Gates Foundation

Wikimedia Foundation

You get the "Foundation" idea - https://en.wikipedia.org/w/index.php?title=Special:Search&li...

PFLAG

Human Rights Campaign

RAINN

Elton John AIDS Foundation

You get the "LGBTQ" idea - https://en.wikipedia.org/wiki/Category:LGBTQ_political_advoc...

Amnesty International

Freedom From Religion Foundation

NORML / NORML Foundation

National Cannabis Industry Association

Sandy Hook Promise

March for Our Lives

Rock the Vote

Paywalled but the argument for scrapping NFP tax exemptions is excellent.

I can only really speak for my experiences in Australia but the Christian churches here are as cutthroat as any multinational corporate, they’re decimating state schools, and moving into service provision, workers and users end up second best to church interests.

Having worked for multiple non-denominational NFP’s I’ve learned charity is a business structure above all.

Charity status should be limited to strictly volunteer run organisations or have strict caps on remuneration.

Render unto Caesar motherfuckers.