Whoever is cheapest, with good coverage in my area.

I don't particularly think any one carrier will have any privacy advantage over another.

I feel like its weird this post is getting so many down votes. I mean it's not the best question, but not everyone would know that phone carriers are equally bad at privacy. Heck maybe in other countries there are some that help privacy.

Lemmy is a global community so the provider I use in my country would hardly be useful to anyone else, you wouldn't have heard of it. Maybe specify which country you're interested in if you wanna compare providers available for you.

All US mobile providers are bad, but I hear the most bad stuff about T-Mobile. I'd recommend sticking to using data whenever possible, avoiding conventional calling and texting, and running a VPN just in general. Less for the providers to find out that way.