I played YuGiOh and Boxball and Dodgeball and all that, but my friends and I were also pretty creative in that we made up a lot of games to play. One was Cannibal Island, which we played a good amount. Basically the first 'level' was we'd all ride around our friend's circular driveway (he had this long snakey driveway with a little garden island in the middle, it was awesome) on scooters and bikes, and there would be a cannibal who basically tagged the non-cannibals. It was kind of like tag on scooters and bikes, but the cannibals stayed cannibals. We added all sorts of things like weapons and stuff, it was a blast.
We also played the 'lego game', which was more or less the Sims with legos and it was fun as hell. We'd spend an hour building this huge city and it was so cool, because in the end I'd always end up a secret agent or a restaurant owner or something cool like that, and it was fun.
Lastly, we played something called Wee Snaw. I know, it sounds retarded, but we heard it in a Spongebob episode one day (Spongebob is seriously the most inappropriate show for little kids, just watch it sometime when you're bored and you'll be AMAZED). It was more or less my own version of DnD, but with all this crazy stuff. Like, one time I decided to be a penguin whose class was a baker, while my friend was like this dragon thing. We spent years playing this, and it was just a great way to pass the time in car rides and other stuff.