First let me say I have never endorsed a product in my life. I am always receiving samples in the mail and most of the time I use them and forget about them. Today I received the Mr. Clean Magic Eraser. You have got to try it! I had marks on my walls that had been there forever. (Marks from when my kids started walking.) There was a stain on one of my cabinets that I had tried every cleaner imaginable to get out to no avail. I just rubbed lightly with this Magic Eraser and it was gone.
You can get a free sample.

Canadians click here.

Americans click here. (Update-Samples are no longer available in the U.S.A. Go and buy one anyway!

I am not sure if you can still get them free but worth a try.