My one I always mention in such threads is the year I got my dd for Xmas a set of plastic drawers from Argos I'm sure you know the type.
Filled with cheap arts and crafts materials but some were specific to things she liked and were a bit of an "in joke" type thing
Her own roll of kitchen foil - she was always nicking mine to make "stars" on collages
A full ream of Cheap printer paper to do with as she wished
Glue sticks of various shapes and sizes
Post it's of various shapes sizes and colours
Scented erasers and pens
Set of gold star stickers (she liked playing "teachers")
I managed to find in a pound shop the kind of magnetic clingy draw and erase boards I used to play with as a kid on long car journeys (I'd tried to explain them to her in a chat about what I played with as a kid and she couldn't grasp what it was) the kind with crinkly plastic top but and you use a stylus to write/draw on then pull it out the side to demagnetise and it clears what you've drawn/written. My siblings and I used to insult each other on them so our parents didn't know we were arguing/winding each other up
I also found her a couple of those bic 4 colours in one pens which she was fascinated by
Plus loads of the usual arts and crafts stuff
It was a cheap, but physically big present designed really to make the pile look bigger at a time when I couldn't afford much. She's now 20 and STILL talks about it.
The set of drawers lasted her ages, when she got past the colouring and collage stage it was used for Jojo bows and other hair accessories, make up, diaries etc
She's done this to me on several occasions the cheap fun gift has been the one she's loved!
One year it was a hula hoop thing but it had like 3 hoops in one and to get it going you had to be really good on balancing it
One that became a bit of a tradition was retro board games that I'd enjoyed in my childhood, usually not the "real thing" but supermarket or pound shop versions. Battleships was a surprising success
One year I grabbed a pack of cards and this also became a bit of a tradition made fun by hunting out fun pack designs but it also led to the grandkids being taught various less popular now card games by my gran!
Jacks was a surprise hit one year
Retro sweets another (mix of sweets from mine and her grandparents eras many of which she hasn't even heard of) bought from local market stall
The year that she was very into baking I managed to find a 50's style frilly pinny which she found hilarious (but also saved her clothes!)
another time I got her an octopus clothes airer thingy - for drying her art work on!