Remember the milk is an old friend.
It has been my Get Things Done (GTD) product of choice now for years.
I just love the way that it works. It's simple interface and the ability to add tasks using simple english was revolutionary when it first came out. I still find it really impressive today that I can write
and this task is added complete with a reminder for the next Monday. Sounds simple right, but trust me it saves loads of time over using a calender picker.
With loads of different ways to prioritise your tasks, group them and even have categories which automatically populate based on key words such as "Call" there is no reason for not getting organised.
RTM works on different platforms, and has apps for most smartphones, allowing you to have access to your tasks on the go. You can even get your daily tasks emailed to you in the morning so that you can plan your day.
I love the fact that the developers have stayed true to the original product and have not cluttered it with lots of gimicks. As such it remains an extremely slick and streamlined offering which will help you get more done.
There is a large user community and lots of people have shared how they use RTM in their life, and give plenty of useful tips as to how to get the most out of the software.
Take a look at their website