To me personally, Jira was the best tool I've used so far (used a few of them, but not very many). But I still was not too happy with it back when I used it -

To me personally, Jira was the best tool I've used so far (used a few of them, but not very many). But I still was not too happy with it back when I used it - main reasons being extremely slow load times (we had the cloud version, not self-hosted) - and lots of annoying inconsistencies, like "create issue" using a completely different editor than "edit issue", etc.