Art or craft supplies. You could build small project kits.
We like to get pictures of our friends, Photoshop them up a bit, print them at someplace inexpensive (like Walgreens) then put them in frames. Cheap, personal, and they usually go over quite well.
I like that one a lot.
This year for St Nicks, my SIL gave everyone home made bottles of flavoured oil. She sterilized little bottles in the dishwasher, filled them with herbs wrapped in orange peel, with a few decorative spices. Looked very nice. Can be done with vinegar, too. It is something you don’t easily buy yourself, but it looks pretty, and after a while, it is used up and can be thrown out. Here are some recipies.
One puzzle, not too hard—like 500 pieces, say—with the pieces divided by how many people will be there. Each person examines their own pile for the next interlocking one.
You could combine that one with the photo idea: have a really nice photograph of all of you (maybe last Xmas) printed as a puzzle. Loads of places do them, but I don’t know about the US.
I also second the nice socks. If you want something fun, how about these? You’d wear them to work under your suit, but secretly you’re wearing silly socks!
I gave those socks to and aspie friend. He can’t deal with patterns, but wanted to practice. In all seriousness, he practices wearing those socks. With shoes on, he’s fine!
That’s an EXCELLANT idea, the photo puzzle.
For these kinds of things - little extra gifts, or a small gesture for someone you don’t know well, or for an office $5 Secret Santa or something - I like to pick up those little miniature books that you see near the counter of book shops. They’re usually on fun random topics like quotes or trivia, or little comic books like Dilbert or The Far Side. The Onion has done some too, I picked up a miniature version of their “Our Dumb Century” book for $5 which is pretty funny.
Like so:
The Onion: Our Dumb Century
Shakespeare: The Bard’s Guide to Abuses and Affronts
X-rated Shots: More Than 50 Shots We Dare You to Say Out Loud