Used many of them. None really worked well.
As a PM, my main focus is just to get people to update what they're doing and trying to assign, distribute, negotiate, and see tasks and dependencies that need to be done.
Asana - Amazingly good in the first few versions. But it started getting slow as they added more features. Back then I would use it even for trivial things like bug tracking, because the keys and controls were so intuitive.
Google Docs/Sheets - It does the job. It's got history and versioning. Low learning curve. It's very powerful at searching (you can link to a document and it will search the linked document as well). Sheets is mildly programmable.
It's missing some tricks like tagging people and tracking who is assigned to what, attaching files, and has a limited comment system. You can't really subtask, map dependencies, or do burndown charts with it.
Jira - Hated it. Its core purpose seems to be covering asses. It makes a PM look extremely productive. It makes late night and remote workers look productive. It logs what people are doing and logs issues and dependencies. Extremely useful for people who have agile contracts for another company. But actually managing people seems to be the lowest priority of the tool.
Pivotal Tracker - Lots of potential. If you're using full Agile, this is probably the best. It's probably too heavy if you have a team of two, but even then it works. I think the Epics handling is a little messy, but it's much better than the others.
Trello - good for assigning tasks to a group. Too light for managing a pipeline from design to dev to testing to approval. At some point, it acts like email, where people get too many messages and ignore a lot of them.
I'm considering experimenting more with Google Sheets and maybe even group Evernotes. The others are a bit too clumsy.