What really are "powerful" backlinks?

[Greg Schueler]

Eric Ward (Link Moses) often said: "Links that would exist, even if Google and Bing did not, are almost always the ones that provide the most value. That's both in traffic and in rankings."

 

[mikepcservice]

Guys, if a site you got a, link from should get penalized, does this mean you will too or have negative effects on your end?