I have NO idea how many lego sets I had. IMHO the "junk" of the sets were the windows, people, wheels, the stupid closed minded stuff. I preferred the raw blocks, mainly the 2x4 and the longer ones that were in such short supply. I mad some amazing things, including a box with a door locked by three tumblers, that required its lego key to open. (if it had been glued together, naturally)
I also had dominos and blocks, two capsula sets (adding a switch, motor, and wires to the mix), an old and a new girder n panel set (kinda meh), tinker toys (also meh), and later a number of assemblable toys like a little battery powered toy boat I had to wind the motor (dc windings) on, a ball clock, crystal radio, and by age 10 two electronic design experimenter (150 and 200 in 1's). I did a LOT of building when I was growing up. (though a good deal of it started going toward electronics by the time I was a teen)
Kids need a shot at that sort of play when they're growing up. It's not going to be for everyone, but this whole culture of "stick an ipad in his hands" by default is just a shame. Ikea is going to go out of business by the next generation, nobody will be able to assemble any of their furniture!
I was just talking with a friend of mine, father of my godson, about the possibility of getting him into arduino. Wow, he's gonna be NINE this December, and he doesn't have anywhere near the head-start I did. I did manage to inspire him with a variety of art supplies which he loves, and got him several of those assemblable bots from radio shack last year, trying to get him a good start and taste of things that he finds he has an aptitude for. It's not just building things, kids need to get exposure to a variety of things as early as possible, so they get their feet wet with essential flexible skills like buidling, as well as getting a taste of variety to see what they really enjoy.
But being able to make things, that's such a basic, universal skill. It's one that every kid should get heavy exposure to, in a format they can enjoy excelling in.