I go through this every year and let me tell you, it doesn't get any better. I now have 3 kids in elementary school and two of my kids change classes, so all told...6 teachers have my kids in their class!! I used to get nice gifts for homeroom teachers scarves, gourmet candies, candles - one year I got them tin signs with expressions like "Joy", "Read", "Because I Said So" LOL!! I loved getting unique things. However, with three of them and more teachers to buy for, times have changed.
One idea is to do it yourself, or go in with other parents to get an animal from www.heifer.org. It's an organization that provides impoverished families with animals from bees to cows. They are able to provide food for their families or sell products with the eggs, milk, honey etc. they get from the animal. My son's class did it last year and it's a special bond they have with their former teacher. You could get a trio of rabbits in the teacher's name or have the whole class go in on a larger animal.
I've also heard that a heart-felt card, possibly decorated with scrapbook items, is always welcomed.
I know that around the holidays, the teacher's lounge is a constant "lazy susan" of cookies, pies, treats, etc. I like the idea of the fruit basket. It give the healthy option!!
I, personally, think you can never have too many ornaments! I know a former teacher who has a separate small(16") tree she has packed with ornaments from her students. Like previously mentioned, make sure the child's name is on it.
Last, but not least, this year my plan is to give giftcards- Barnes&Noble, because they can use it to find something for the classroom or use it for personal use. It won't be much, but even $10 off a book for $20 is a great deal!!
Good luck!