Just turned 5 year old - yoto player; child size fishing rod from grandad.
2 year old - enormous box of Brio-type train set (secondhand off FB marketplace). He already had some but now he has enough to build complicated tracks all around the dining room.
Both of them have loved Hungry Hippos, well actually the John Lewis version which is Snappy Crocodiles. You would have thought this had quite limited play value but they somehow played with it non-stop for 2 hours this morning.
The 5 year old got the Orchard Toys bus stop game for his birthday which they did the same with.
2 year old got Happyland farm for his birthday, again secondhand, again very well loved and his older brother helps him play with it too.
Last year the older one (so 4 yo then) got a projector light for his room which shows pictures of the solar system/constellations on the ceiling, which he still uses most nights.
The year before that when he was 3, his best present was a child size litter picker and hi-viz jacket! He picked up all the wrapping paper from Christmas and we spent many Saturday mornings in the park dutifully picking up litter.
Other big presents have been scooters/balance bikes/pedal bikes and the accessories - for his fourth birthday we added light-up handlebars, lights, a bell and a windmill to DS1's existing micro mini scooter and I think that might have been the best-received present I've ever given either of them.