What Are The Best Ways To Find New Links?

So I've been in SEO for a little over 2 years now, and I've spent some time developing a small list of powerful links; however, I can only imagine that individuals out there have different links from a variety of different sources. I wanted to ask what has been the most effective way to find quality links for you? I would be open to exchanging link list, but I know some people tend to get offended when offered.