Cars (anything with wheels), sturdy flap books, those wires on a wood block with beads to move along a la doctors surgery, cars, stacking blocks or stacking rings, and did I say cars?! (Would recommend the WOW series of toy vehicles, they're just the right size, have little people that are too big for swallowing and they move without batteries)
I agree with Apuski, Wow toys are brilliant. My son has played with the same couple of Wow toys for the last 2 yrs. If they are boys then cars will go down a treat. I didn't go too mad for my son's 1st birthday as he wasn't really into toys and would rather bash a pot with a spoon or play with tupperware. I don't think its worth splashing out too much for this age.