“Duplo (and then Lego) are fantastic. So are plain wooden building blocks (and to a lesser extent mechano and konnex). In fact, I feel like playing with them now…”
lmao
Dr Seuss books yo 
Lol dinosaurs. When I was a kid, I was obsessed with dinosaurs, basic science, video games and books. You should encourage reading as much as possible. That’s what got me into learning. If he likes dinosaurs, get him some dinosaur books with pictures and descriptions. Video games shouldn’t be too much of a problem, as long as you keep a limit on it.
I just read a book, “Structures: or why things don’t fall down”, so I’m suddenly interested in building stuff again, out of blocks (as an imitation of cathedrals, castles and other masonry stuff). I always loved building things. I’m not going to stop liking building stuff just because some people might think it’s childish 
Anyway, when I was a child, I needed barely any prompting to do stuff that was ‘educational’. Just a nudge in the right direction was enough. In fact, too much pressure to do something (that I thought would be) boring would put me off it. Just give a kid a pen and paper, and they’ll do all sorts of creative things, just as long as you’re willing to take the time to show an interest in what they’ve made (even if it may be rather crappy a lot of the time).
Worth a read:
http://daviddfriedman.blogspot.com/2007/12/home-unschooling-theory.html
http://daviddfriedman.blogspot.com/2007/12/home-unschooling-practice.html
oh, magic tricks!
These are actually great learning tools for children I think. They are fun to do and not only illustrate that one can do seemingly magical things with practice and skill, but more importantly they also illustrate how easy it is to be tricked if one isn’t always questioning what one sees. Sounds like a pre-req for any scholar.