My wife got me a tennis calender for my office.
My kids got me the book 'Andy Murray Champion' by Mark Hodgkinson - I have almost finished it and would recommend it.
My sister got me 20x Wilson US Open tennis balls.
I am the only earner in my house and could have bought myself any of these (I suppose I did really but I dont see it as 'my' money) but enjoyed getting them as surprises, particularly when my tennis/Andy Murray mad 7 year old daughter was really excited to see me open the book. I do stop buying books in the run up to Christmas to leave things for others to get me. I can always buy whatever I wanted after Christmas if it didnt arrive in a parcel.