though at this point it is kinda predictable - all news sites, except the ones with paywalls (and if you haven't bought the subscription, then its pointless visiting them). All information sources, except a few notable exceptions (usually aggregators like HN/Reddit, but also Medium).
Everything else divides into SaaS products, personal blogs and random shit. Random shit is usually ad-supported, the rest are usually fine.
it's all sort of moot anyway - the ads model is crap and getting worse, and businesses are going to have to move to something else soon. I don't think we'll have this problem long.
I'm often told in advance, by virtue of it coming up in a search result, promoted link, friends post, etc.
"This site contains adverts that perform obtrusive tracking" is seldom mentioned before or during the visit, the only way to know is by trying to block all such things and seeing the site fail if it tries to block the blocking.
Sometimes the advance information of content relevance is deceptive of course, and this often coincides with darkest patterns in the advertising/tracking.