As a teacher, I appreciate gifts of things I can use in my classroom. Pencils, crayons, markers, stickers, paper, notebooks, etc. So many kids come without any supplies.
I, personally, do not like receiving gifts from the kids. The children who don't bring anything in always feel terrible, so I encourage all the children to just make me a card.
A note from a parent showing appreciation would be valued by me much more then anything you could buy.