Kitchen play stuff, indoors and out. Outside we have heaps of op shop stuff that they make mud and sand pies with, metal saucepans etc and bits of wood for the kitchen. Doesn't have to be fancy.
Craft stuff - our dining table is now a craft station, I have one of those 8 hole file things with paper, glitter, glue scissors, magazines, stickers, ribbons, pom poms all sorts of stuff and she can sit there for ages making stuff. I collect all boxes for that reason too for painting etc.
Roll of paper (ours is from Ikea) that I just roll out on the floor - can be used for loads of stuff like tracing around bodies and decorating or just general drawing.
Rolls of contact - they can be stuck on windows with sticky side facing out and you can stick cellophane, dirt, leaves, etc on it - no glue needed.
Role play - Iz is happy to make "beds" all over the floor like they do at creche and she puts all her dolls to bed, strollers as well.
Books.
CDs with kids songs - we love Justine Clarke and Jay here, happy music that we put on and they dance around while playing.
Train tracks and trains. We have tonnes and instead of making tracks on the train table now they do it on the floor and all around the house.
Building blocks plastic and wooden.
Mr Potato Head - classic and mix him with Play Doh and you have yourself an hour of fun making new creatures!
Craft related to books we are reading - for eg. a few weeks ago it was rainbow fish so I cut some out and lots of coloured circles with foil and kinder squares. Add goggle eyes.
Painting on foil instead of paper - looks great and is a novelty.
Puffy painting - S/R flour, a bit of salt, food dye and some water to make a paste - paint onto cardboard and then microwave for around 30 secs - voila puffy paint!
Um that's all I can think of for now - can you tell it's been a loonnnnggg cold snotty winter in Melbourne