[manigandham]

A simple text file has always been far faster and more useful to me than any of these to-do apps. Lately it's migrated to a text file on dropbox, or using google docs or box notes for cloud sync.

There's also TaskPaper which is nice but only on Mac https://www.taskpaper.com/

[Pxtl]

I've been using Google Keep - it has a list of checkboxes for this, they hide when checked. The upside is that you can drag-drop reorder then and you can add to the list from voice on the homescreen ("okay Google add book my vacation time to the Todo list").

But it fails one power of plain text rule - I can't copy and paste into and out of it. Sucks when I want to send snippets of my shopping list to my wife over sms.

[manigandham]

I do use Keep for notes. For todo's though, the web UI is nice but too slow and annoying to use. Nothing is faster than a text file.

[dragly]

If you want to quickly add new tasks to your todo.txt from the command line, I strongly recommend http://todotxt.com/ It is a fantastically lightweight solution and has an Android app for those times when you are not in front of a computer. The Android app just reads/writes to the same todo.txt file over Dropbox.

[davejamesmiller]

There is TodoPaper, which seems to be a clone of TaskPaper for Windows. http://widefido.com/products/todopaper/