Link exchange. You can do link exchange for dofollow links. it is little bit expensive because you have give link at your back link site, but it is most beneficial to in Google ranking and every link you can take as you need (dofollow). Regards
LinkExchange is not liked by google for long term, for some time it may give you a SERP boost but soon you will note the bad effects. For which site you want to get links ? I mean blog or money site or what type of site ?
Your site's ranking in Google search results is partly based on analysis of those sites that link to you. The quantity, quality, and relevance of links count towards your rating. The sites that link to you can provide context about the subject matter of your site, and can indicate its quality and popularity. However, some webmasters engage in link exchange schemes and build partner pages exclusively for the sake of cross-linking, disregarding the quality of the links, the sources, and the long-term impact it will have on their sites. This is in violation of Google's Webmaster Guidelines and can negatively impact your site's ranking in search results. Examples of link schemes can include: Links intended to manipulate PageRank Links to web spammers or bad neighborhoods on the web Excessive reciprocal links or excessive link exchanging ("Link to me and I'll link to you.") Buying or selling links that pass PageRank Source : Google webmasters guidelines, Read more at http://www.google.com/support/webmasters/bin/answer.py?answer=66356