I am currently self-hosting a meta search engine instance (searxng), which allows me combine searches from different engines (e.g. Google, Bing, Yahoo, etc), but also to filter out websites that I don't want to show up.
The only website to make my blacklist so far is slant.co (useless SEO-riddled site that always comes up when I search for software comparisons). I also automatically redirect all reddit.com links to old.reddit.com.
I'm looking to expand this list. So, which websites do you blacklist? Either using software, or just mentally.
*://picclick.com/*
Just reposts old ebay listings as far as I can tell. I guess it could come in handy if you want some historical price data or something, but it mostly just craps up the search results.