If you're looking for a great all-around author who might work for any readers for whom you are seeking gifts, you really don't have to look any farther than Wendell Berry.
The guy's a super-talent. Not only is he a thoughtful human being, but he writes in a variety of formats, and he writes well in all of them.* And, he publishes often enough that even people who are only interested in new books have lots of options. Some of my top picks:
Bringing It to the Table: On Farming and Food: A wonderful collection of essays about food, agriculture, and sustainability. This would make a good gift for anyone interested in those subjects, any of the more environmentally aware people on your holiday list, or anyone who simply enjoys good essay writing. Foodie readers might also get a kick out of this one.
What Matters?: Economics for a Renewed Commonwealth: Another great recent essay collection focusing on matters of economy and agriculture. This one would work for the sustainability crowd, but might also be of interest to any people you know who enjoy business or economics books.
Jayber Crow: Berry's finest novel, in my opinion. A classic. It would work for anyone you know who likes character- and setting-driven fiction, and doesn't mind a bittersweet twinge to their storytelling.
Given: New Poems: A poetry collection that might be good even for people who aren't crazy about poetry. Berry's poetry is just like his prose; clear but evocative, and timeless. Everything you want poetry to be.
*It's a bit disgusting, really, that one man got all this talent.