If you're referring to topsites, they are archaic, their rules are outdated, and they optimize for speed over quality of releases.

In terms of breadth and quality of content, private torrent trackers are far and away the best download method.

Usenet

Unless you're using private NZB sites with encrypted/obfuscated files, usenet is nowhere near as good as it used to be.

Even then, private torrent trackers are better for choice.