Please, not a teapot. Every few years we get a lovely teapot that has been decorated by all the children in a class, pottery cafe style. It is utterly useless to us, as nobody has the time to sit down with a pot, and in staff meetings there is such a variety of drinks that there's no point making a pot. We haven't the heart to get rid of it, so it clutters up the staffroom until it breaks. Occasionally a staff member will take one of the pots home, but only after a few years have passed.
Non-food staffroom gifts that have been very much appreciated in our staffroom:
A dozen good china mugs. We were able to get rid of the chipped mugs, and the ones that were so 'robust and chunky' that they were heavy and barely held two mouthfuls of tea.
Dishwasher-safe travel mugs for the playground and FS/KS1 (where we are not allowed uncovered hot drinks). I think they were from Costco, because I'd been coveting the very same ones, but they came in packs of three.
Huge, squat, biscuit jars. Not metal tins that take two hands to open and are noisy and fiddly to shut. Jars with a lid with a knob, or a clip like a Kilner jar, with a very wide mouth, so that you can open it one-handed, take a biscuit and close it one-handed, while your other hand is full of work to mark (or tea in a nice china mug 
).
A coffee pod machine. 50-50 on this one as many of us do not drink coffee, and the pods are relatively expensive. (It does hot chocolate pods as well, but the hot chocolate was no better than what I could make by hand and in the same time. And, at £1 per pod, not worth it.)
A condiment set of pepper mill and salt mill. But the clever thing was that they are upside-down mills - no mess!
Sets of nice hand towels and tea towels. A staff member takes them home each week to wash, but they do get grotty and worn very quickly, so it's really nice to have new ones.
An Ikea gift card - excellent!