I use the list-making tool within Google Calendar. At least, I do so in cases where the list needs more permanence and accessibility than the back of some other document, which is the natural medium for scribbling things down.
I choose Google Calendar mainly for the reason Becky gives in her post, to keep the number of subscriptions low. It also offers the advantage of displaying the lists alongside the calendar without necessarily integrating them into the calendar. The reminders of things still to do may therefore be kept in sight, but unaccompanied by evidence of how far I am past the date by which I once hoped they would be done.
Had a bash at being whimsical with LinoIt.
And I will bear LinoIt, TeuxDeux and the rest in mind should Google Calendar's list-making facility cease at any time to be available.