Best Task Mgmt for Mac/iPhone/iPad/Android?

Create shared To-Do lists, shared tasks, set deadlines and reminders and snooze them, ping your colleagues when they're late, attach files, comment on your team's tasks, search and filter your tasks, create sophisticated work reports, send tasks and receive notifications on your email, IM, twitter and mobile phone...

Wunderlist is an easy-to-use task management tool with cloud-synchronization. It works on Windows, Mac, iPhone and iPad (Web and Android coming soon). You can sync your lists and tasks over the air, so you are always up to date.

Strict GTD implementation, with iPhone and iPad apps that sync nicely. It's very 2.0ish, and has a useable mobile web version (for use on Android).

Springpad is a nice app, iPhone, iPad, Android and Mac. Great ppl with great support as well.

Great GTD app. Avialable on Android, iPhone, Windows, Adobe air with cloud synchronization. Similar to THINGS but free.

TeuxDeux is a simple, designy to-do app for the browser and has a native client available for iPhone.

Web/iPhone/iPad and there might be a third-party Android app. This is the one I use.

Good, but has only iPhone, iPad and Mac support (no Android). Also, it lacks true sync, i.e. you must be on the same network to sync, and I want to sync via the cloud...

This is my phone that seems to be a pretty good. Founded the other day when i was looking for cloud basic versions, and it appears as they added support for this. No Android support.

An Android/Web to-do list that specifically focuses on collaboration. It has a simple interface with unique features such as voting and comment communication.