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