Space Dust - we used to buy a couple of packets and stuff the whole lot in in one go. You felt as if your head was going to explode.
Also - remember kayleigh (kalie, k,lye or something). Basically sugar, colouring and flavouring - you'd buy a bag, lick your finger, stick your finger in and suck the sugar back off (is it me, or does that sound highly suspect?). We'd either buy it from Coombes in Sutton (great shop) or make our own - I have a sneaky feeling Blue Peter taught us how to make it!