Project Management Software? What is the best?

What team building software do you use/prefer? 

I have used Evernote, Monday and Slack in my advertising jobs. I prefer using Slack just because I like the interface and fun interactions. I also think it is more scalable than Evernote. 

I am wondering what software Instructional Designers prefer in their workday?

A couple fun facts about #Slack and Monday.

https://www.fastcompany.com/3026418/this-story-about-slacks-founder-says-everything-you-need-to-know-about-him

https://www.zdnet.com/article/how-to-build-an-efficient-collaboration-system-with-slack-and-evernote/

http://comparecamp.com/monday-com-reviews-pros-cons-pricing-popular-collaboration-communication-software/