Living in Australia at the moment, and some of the stuff I would miss off the top of my head:

Fun fact: Wunderbar is actually the special-edition peanut butter version of this chocolate bar. I like the original better.

Quite possibly the best soft drink ever made.
Some Canadian stuff I miss:

We actually have a Kicking Horse Coffee stockpile. It's actually really hard to find non-espresso coffee at coffee shops here. Otherwise, people seem to drink putrid instant coffee.

etc etc etc
I try and substitute Toohey's Old but it's not the same. It seems to me that places with cold weather tend to make better beer (UK, Canada, Northern Europe). With all due respect (and maybe I'm looking in the wrong places) but 95%+ of Aussie beer seems to be the exact same slightly hoppy lager - at least in QLD.