I have been teaching for 20+ years but fortunately the last 14 have been high school only so I get very few presents.
My favorite gift was a little hand painted ornament made by a third grader - I had him again as a senior - he ended up being a phenomenal artist.
I would also suggest staying away from any homemade food items - most teachers I know won't eat it unless they know the kitchen it came from.
Suggested giving for teachers
I don't know what price range you are looking but here are some suggestions
Elementary teachers:
Stamp and ink pad
Congratulatory stickers
Bib type apron
any teacher:
movie rental certificates
I've known class mothers to take collections and get 1 big certificate for a restaurant.
Movie tickets (we can get discount tickets through our credit unions)
flavored coffees or teas
certificate to a "teacher aid" store if there is one locally
Staples or Office max certificates.
Book store certificate (or amazon.com credit)
Hope this helps someone out
It's about the journey and being in the moment, not about the destination