Most students of all ages seem to appreciate nice pens. Older boys tend to like the stainless steel Zebra pens, which can be bought in large quantities like this and this. For smooth writing, Uniball Jetstream pens are really nice. I’ve noticed that many girls like having pens with unusual ink colors.
My school-age children (ages 7 and 9) have received water bottles and plastic travel mugs, and were very happy to get them. They are used regularly.