pass
I like the fact that it is a minimal and simple program that does one thing, and does it well. If you already use GnuPG for encryption, you will get used to it quickly.
The only downside for me is that it doesn't encrypt password names, only the content.
It also has many plugins and android/ios apps.
I would like to highlight the browserpass extension for Chrom(e|ium) and Firefox (and derivatives) which allows you to enter credentials into web pages without having to copy from a terminal.