My favourite lunchbox snack was the ubiquitous choc chip muesli bar, but it had to be the Uncle Toby's brand. Jadedoz will know what I'm talking about.
I also liked Le Snak, another Uncle Toby's product, which was like a savoury version of Dunkaroos. You got a couple of crackers with some cheese dip.
Probably the snack I got most often were those mini bags of potato chips that come in big bags of 30. It's good to be a kid and able to eat all that crap without health repercussions... :D
On a related note, somewhere around the second or third grade I developed an intense aversion to bread, so I used to just throw my sandwiches in the trash at school until my mum found out and and tried to get me eating other stuff, like pitta bread and foccaccia and such. I have no idea why I suddenly turned off bread, and it's only recently that I've been able to eat it again (although it has to be same-day-fresh, and chilled in the fridge). Weird, huh?