Toys that stand the test of time (and some mentioned already)
Big set of wooden blocks
wagon
small tricycle
Big dublo blocks
toy kitchen/food
Good simple musical instuments (I loved kindermusik ones)
cozy coupe if you don't have one
art supplies (paper, paint, fingerpaints, crayons)
dress up (get simple and solid
chalkboard/chalk
My kids loved the plastic (little tykes?) rollercoaster thing that you ride on.
I know it's tempting to buy all those toys in commercials. However, the day that DH looked on our front porch, and saw all of last years toys waiting to be picked up by goodwill, so we would have room for new toys, made me evaluate my buying based on how long they will play with things. I've found the tried and true toys really do get played with most.