We do food each year. It always goes over well and I've gotten requests for recipes several times.

In the past I've done cookies, muffins, candy, cinnamon almonds (hands down my favorite), these little
pretzel chocolate thingies (also a favorite among teachers).
This year we'll probably do the nuts, the pretzel thingies and some different popcorn (in one of my cooking magazines they just had 3 or 4 different recipes that looked yummy!). I found little popcorn containers at Target for 2/$1 that I'll use and wrap them in holiday wrap. I think I'll do 3 different kinds of popcorn for each teacher.
DS has 5 different teachers that we'll gift (his 2 regular ed teachers (they have joined classrooms so he's with 1 teacher half the day and the other teacher the other half the day), special ed teacher, personal para/aide, classroom aide). He also has an OT and a SLP that we'll probably give a smaller goody basket to.