Paper. just a single piece of 8.5x11 paper. Anything more complex means I'm trying to do more work than I can handle.
An old colleague of mine.. and CFO of our company.. used to manage his tasks on a piece of paper. It was always in his folder, and for each task he'd write a note on the paper and then draw a box around it. As he completed each task, he'd scratch out the box. It was crude and messy and reminded me of high school. A couple of years ago, I found myself migrating towards something like it. I use large index cards, but..…
I kept a digital list for a few years, but eventually it just became a crap heap of undone tasks and abandoned ideas that would get batch re-scheduled forward forever. Paper lists work really well for me.