Quality is most important but if you get quality with quantity than it will be more benefited for result...
Definitely quality search engine friendly links is what you need. But like seo_specialist said nothing like it when you have large quantity of quality links
If you have a single link from the yahoo homepage, you can rank high for even competitive terms. while yahoo allows the link to persist if you have 100,000 backlinks from tiddlers, you'll get the same effect, but you won't be at the mercy of 1 (or a few) 'big boys'. go search google for stock trading tips and then analyse the backlinks for the number 1 result for a demo of this. Hint - google backlink tool only shows links from site with high pr. Yahoo will show ALL backlinks.
Quality is more important on building backlinks because search engines give more significance on this. But its better if you have more (quantity) quality backlinks...
I guess you already knew the answer before posting here. Quality is more efective than quantity. Though, if you take a look at the pagerank table ( google search it, first result) , you'see some algorythms. Depends on your methods, if you are able to get 3019789574971259 links, do-follow and following the rules, then do it . If not, stick to quality ones. IF you take your time and start reading threads from " Link building " here in DP, I am pretty sure you will find QUALITY and QUANTITY links. Best Regards.
I consider both but of course you want to spend times getting quality links first. If it's a backlink, then it has some value and help my ranking.
Quality no doubt. You get 1 backlink from a PR10 OR You get 10,000 backlinks from PR0 You'll rank better for option A