DH's office does Secret Santa. Everyone has the option to not participate, and there is no issues if you don't. If you sign up, you fill out a form about your likes and dislikes; then your name is put in a hat and is randomly drawn. There is a $10 or $15 minimum, I think; not very much. The rules say you don't have to say who you are, but you can; there is a date that all presents must be under the office tree (and there are always a few extra wrapped gifts the HR lady has, in case someone's SS bails, but that has only happened once, and that was because the guy was let go). On that date, after lunch, SS all get together in the conference room and get their gifts.
DH has received some meh gifts (a Christmas projection light from the Dollar store, and other random stuff like that in a plastic bucket his first year) to amazing gifts (a $50 bottle of Whiskey a few years ago). If the person fills out their form, he'll go off that, if he can; otherwise it's "hey, we're going shopping to find my SS gift", and at the store looking at random stuff "yeah, this is it."
He's been at companies that have done White Elephant gifts. One year, he took a movie pack, with some DVDs of Three Stooges movies, microwave popcorn, Raisinettes, a 2 liter bottle of Coke, and a rubber chicken, in a popcorn tin. That year, he brought home a web shooter, that shoots silly string.