I use MyLifeOrganized for Windows. I'm a big fan of creating hierarchical lists of projects and tasks and this tool allows me to do that.

My organization uses FogBugz to manage our releases, projects, and tasks and I can't say enough great things about that software.

Mostly Trello..

Droptask (http://droptask.com/) for a change.

I use Asana for work, and I use the checkboxes on the Momentum chrome app. I don't always follow that religiously, so I write things out on pen and paper every couple of days or so if I'm feeling chocked. Not super efficient, but it's sort of working for me.

Trello + Highrise + Bitbucket/Github Issues + Email + Calendar

Now that I look at it like this. What a mess. A necessary mess I'm afraid.

On our current project (which is quite big) we use Mingle.

OmniFocus for my own stuff, Trello for team tasks.

Trello + Google Docs Works like a champ.

Slack feeding a task list bot.