Here's a list of things we really like:
- Flexibility; we can customize things like themes, spaces, and statuses (workflow);
- We can use Filters to view and manage items;
- User Interface is clear and polished and provides us with great User Experience;
- Integrations; we can use external apps e.g. to track time spent on specific item;
- Cross-device and multi-platform; Android app is available in Google Play store;
- Multi-assign; You can assign more than one person to one task!
- Responsive Help Desk - very kind team, they will reply in hours, not days :-)
- Fast development - a lot of new useful features came up since we're using ClickUp;
- Ease of use and simplicity;
- Views: you can use board, list or a box view to manage the issues;
- It's stable - no major bugs even after introducing new features.
I don't remember more but the list of things we like isn't complete... You'll love it, I'm pretty sure about it :-)