I have an older daughter and a younger son!
But my kids are 4 years apart.
At 2, well my boy liked:
bugs, cars, trucks, balls, the Leapfrog "Leapster", play-doh, puzzles, finger painting, zoo animals and figures, farm animals and figures, Dinosaurs or dinosaur stuff. Drawing stuff. Crayons.
Get him a Tricycle!
For your son, what would also be useful/cute, is to get some "boy" colored baskets/bins, and have only his toys in that... and when he gets older or even now, he will know which is his own "special" toy baskets to put his stuff in or when he helps you clean up.
I know... Girl things can really take over a house. I have a girl. Egad, her stuff can get all over. But she and my son play real nice together and he even plays "Littlest Pet Shop" with her. And she plays boy things with him too.
So by now, my son is 4, and he now has a real nice collection of only 'his' toys/boy stuff. And in one part of the play room is 'his' section. He is real proud of that.