DS1 played a lot with his train table and play kitchen from 2.5 to 3.5.
DD liked both at the same age, and will still play in the play kitchen with DS2.
Ds2 doesn't seem as into playing trains. I think with two older siblings he gravitates more toward big kid toys (for ex, he likes to play playmobil with DD...he is very young for PM, but loves it. He may get a PM ambulance or police car for Christmas).
I'm stumped on the one bigger gift thing as my DS1 and DD are each getting one big gift, a few books, audiobook CDs, etc. and then their stocking. We have so many toys from DD and DS1 that I'm out of ideas for DS2.
Oh, DS1 got a trike with pushbar for his 2nd bday. He got a balance bike for his 3rd bday. DD and DS2 were riding the balance bike right around their 2nd bday. DS2 can glide, balance, turn, etc. easily on his right now. If you don't have one, that would have some lasting play value.
Learning Tower? (space hog, but we have used ours for 7.5 yrs and it still looks great. We still find it very useful). Some people don't like the space they take up or don't find them useful, but there are many fans on the BBB.
Easel with paper roll? (for some kids that's a strike out, so YMMV)
Magnatiles? DS2 loves them, and all 3 of my kids play together (2 sets; we really could use a third set!). Again, lasting play value in my experience.
Mama to DS-2004
DD-2006
and a new addition-ds born march 2010