Empty pad -- I like it better that way. Sometimes my "TODO List" involves mockups or doodles, sometimes it involves sub-todo lists, etc. I like the flexibility.

I also only use a red pen for checking things off. Not sure why; it just feels better.

Seems to 'just' thick paper that you can write on, paint on, stick things to - like a scrapbook (http://www.strathmoreartist.com/visual-journals.html)

For me it's just empty lined paper. I much prefer that to all these fancy solutions.