You haven't stated your geographic location... but the common paid/legitimate approach is https://f1tv.formula1.com/ if it's available in your area. If you are a sky subscriber, I think they have an online thing too.
Mods are working on community rules, and starting next week discussion of pirate sources will be against community rules. For now they're taking no action on piracy threads and than to make an advisory comment similar to this one (I'm not a mod though), as they haven't finalized/published the rules. But non-legit sources won't be kosher to discuss next week.
While you most likely ment free services, I cannot recommend F1 TV top much. It costs only 10€/M which for me is 1.5 beers in bar less every month. I have been able to share my account with few friends and quality is really good.