in my niche, the top ranking web sites have mostly SPAMMY links.
I'm a true believer into the mindset that Google cares a little bit about quality, but mostly on the diversity of the root domains that your links are on.
Yes, quality link might be worth more, but not a huge bunch.
If I look at all the keywords I would like to rank high for in my niche. using Moz tools, I can tell that why other sites outrank me is entirely because they have links from many more root domains. For every single keyword of the 150 I monitor.
If you look at WMT, the way they display site links as root domains first, kinda backs this up.
The moral, worry about links from as many different root domains as possible.