Looking for test case management system

I'm trying to choose a test case management system for my project and would like to hear your opinion about following options:

1. Atlassian Zephyr
2. TestLink
3. Gurok TestRail
4. Microsoft Office Excel
5. Google Spreadsheet

In case if you don't want to fall into deep discussion please fill in the voting form below: https://goo.gl/6l2dr4