Remembered my school days are mainly what you guys have
mentioned;
Primary School
1.) Eraser and sometimes bottlecaps so that we pit our thumb skills
to capture those "prized" stuff.
2.) Collected WWF (World wildlife) sticker books, (Think now kids
still have this habit of collecting stickers). Sometimes really
envious when my frens have completed collection of 2-3 books and I
still stuck with 2-3 stickers for that single book..... 
Secondary School
3.) Basketball and Upper Deck cards. That time, the most prized
ones are the American dream team (BAsketball) (Michael Jordan,
Charles Barkley, Karl Malone, John Stockton, Magic Johnson...etc
etc) cards which they represented in 1992 Barcelona Olympic
Games.
4.) Played Role Playing Games (RPG). Not the ones that is on the
computer but actually fantasy role playing games. Remembered used
to owned those 4 sided, 10 sided and 20 sided dice. Not really into
Dungeons and Dragons (RPG) but more on Robotech and modern RPGs
because that time, some western teenager played D&D so much
that he thought he is the character and killed his parents. Sad
story.
Anyone has done the above as mentioned?