Privacy
Windows Telemetry Block
https://www.oo-software.com/en/shutup10
Do Not Track Header
Sites do not have to listen to the header at all, it's more commonly used as a signal to help the ad companies identify you, do not use it.
https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/DNT
Site Opt Outs
https://myaccount.google.com/data-and-privacy
https://app.plex.tv/desktop/#!/settings/privacy
https://www.plex.tv/about/privacy-legal/#plex-your-privacy-rights
People Search
https://www.intelius.com/optout
https://www.whitepages.com/suppression_requests
Data Brokers
Acxiom
Acxiom Opt Out https://isapps.acxiom.com/optout/optout.aspx
Epsilon
Epsilon Opt Out https://legal.epsilon.com/dsr/
Oracle
Oracle Opt Out https://datacloudoptout.oracle.com/optout/
Equifax
Equifax Opt Out https://www.optoutprescreen.com/
Experian
Experian AIQ Opt Out https://www.experian.com/marketing-services/aiq-opt-out
Experian Mail Opt Out https://www.experian.com/privacy/opting_out_direct_mail
Experian Phone Opt Out https://www.experian.com/privacy/opting_out_telemarketing
Experian Email Opt Out https://www.experian.com/privacy/opting_out_emai
CoreLogic
CoreLogic Opt Out https://www.corelogic.com/wp-content/uploads/sites/4/downloadable-docs/teletrack-out-opt-form.pdf
The Big Four Credit Bureaus Equifax, Experian, Innovis, and TransUnion
Equifax, Experian, Innovis, and TransUnion Opt Out https://www.optoutprescreen.com
Clearview
Clearview Opt Out https://app.clearview.ai/privacy/deindex
Peekyou
Peekyou Opt Out https://www.peekyou.com/about/contact/ccpa_optout/right_to_know_and_delete/
Topad
Topad Opt Out https://privacy.tapad.com/optout.html
ISPs
Many ISP's operate some kind of service that tracks you, and only a few of them allow you to opt out of the service.
Some ISP's will record all your DNS query history when you use their own DNS servers, this data then may be sold to others. Other ISP's will redirect you to ads if you try to browse to non existent domains, which in turn may contain additional tracking. You can avoid both of these issues by using a custom DNS resolver with DoH/DoT or a VPN.
A VPN service will usually bypass any measures the ISP has deployed to track you, however your ISP may be able to see you are using a VPN, which may be a Terms of Service Violation, or open you up to being accused of using your connection for business purposes.
Some mobile networks will log sites you visit, you should use a VPN on mobile networks if possible.
United States
AT&T
All residents in the US should be able to use the main opt out service https://www.att.com/cmpchoice
Residents of California may also get extra protections https://www.att.com/cmp/ccpa/dnsatt
Sprint / T-Mobile
http://www.sprint.com/mychoices
T-Mobile don't have an easy opt out, however you can opt out on a per browser basis https://optout.networkadvertising.org/?c=1
Verizon
Verizon make it slightly more difficult and try and make you call them or send a letter, you can find information and instructions https://www.verizon.com/legal/notices/customer-cpni/
You can also opt out of the "Custom Experience" in the My Verizon apps privacy settings.
Comcast(Xfinity)
You can opt out https://www.xfinity.com/privacy/requests/choice
Canada
Telus
You can opt out https://insightsoptout.telus.com/opt-out/telus-lbs/index.xhtml?lang=en
Bell
You can opt out https://www.bell.ca/email-updates
United Kingdom
Virgin Media
You can opt out of advertising and tracking on DNS requests https://my.virginmedia.com/advancederrorsearch/settings
Sky
You can opt out of some tracking and ad tailoring https://www.sky.com/myaccount/my-details