npms.io is a great npm package search with deep analysis of package quality using a myriad of metrics. Much better than the official npmjs.com search.
$ npm install --global alfred-npms
In Alfred, type
npm, Enter, and your query, to search for packages.
Select a package and press Enter to go to its GitHub repo.
Hold Alt when pressing Enter to go to its npm page.
Press Shift to view its readme in Quick Look.
The search is made with
boost-exact:false by default. You may pass any npms.io operators.
MIT © Sindre Sorhus