Friends with Boys - Opinions Please!!

So, Samuel is turning two a week from today. Wow!! We have been brainstorming about what kind of gifts he would truly enjoy. He's getting wood blocks from Mojo and Papaw, which will definitely be a hit, and we will enjoy playing with them too :O) But, I have no idea what else he might like and be able to enjoy for at least months, if not years, to come. Any ideas?