It's very hard to address this question directly because of assumptions. For example, just because there are irrelevant or paid links for the top ten results, that doesn't mean that those URLs are ranking because of those links.
At Pubcon Matt Cutts discussed the "10,000 bad links situation" that the NYT recently reported for a high ranking site. He said his team checked all those "bad" links - and found that their algorithm was already ignoring every one of them. Links can be ignored, rather than causing a penalty.