wikipedia ? Just wondering I tried writing a article before and the link was gone the next day I think. Taken down even though they had no article about my subject , by the commie editors. How fast do they take them down these days - and does a link from them actually help you out at all ?
I think wikipedia know have nofollow on outbound links. However many seo analysis tools give value for wikipedia links.
I don't know how they monitor it so well but links get taken off pretty fast. A day max if you are lucky!