JIRA is a bit like linux. It only really sings when you have a skilled admin to set it up and maintain it.

I have used a whole bunch of ticket/project managing tools in a number of different orgs. By far the most useful is JIRA.

taiga.io comes close, but lacks the admin interface and multi project overview that jira has.

Trello is ok, but terrible for large teams, or large projects. Subtasking is a pain and there is no real concept of a sprint. its ok for replacing notes on a board, but terrible for recording state.

Some of these criticisms are valid, but compared the competition[1], I'd choose JIRA 7 times out of 10.

[1] dont get me started on the "clever" people that decided to make their own in house solution, kneecapping the entire planning ability of a 70k person org.