For me, persnally:
Nothing food-related at Christmas, i'm fat enough as it is and with all the hot chocolates, matchmakers, Turkish delight, mince pies, brandy butter.... I don't need more sugar. Fine for birthdays, though.
A lovely mug any time of the year, good size, good quality, with a design of something the giver knows i like (for me nothing like Disney/Harry Potter, nothing jokey). My favourites are one with books on it and one with an intricate Morroccan print, both gifts.
I sew a lot, so a prefect gift for me would be: sheets and sheets and sheets of felt! Embroidery floss, ribbon off-cuts galore, nice A4 binder to keep my templates in (currently looking at mine and it's a dull as fuck business grey lever arch folder, functional but boring!). A new Projects notebook, cos mine is full. Fat squares, matching threads, assortment of lovely buttons, preferably vintage 50s style (actually cheap as chips and found in charity shops).
Stationery: notebooks, pens (I've bought myself a cheapy but cute E5 fountain pen for my cracker this year! I make the crackers from scratch and fill them).
Little zippy bags to hold thing in my handbag. I have one for my mask, i'd like one for holding handwipes and tissues, these often fly round my bag and they open, get sticky and yuck. Actually a nice-smelling slightly fancy antibac handgel would be really appreciated at the moment, as a PP suggested upthread.