irish invade canada, 2009
thought i'd post these links to cheapie airlines
we've travelled air transat before - they go from dublin and shannon
there is also a charter that markets itself "a canadian affair" (fintan, stop laughing)... they go from belfast, also from loads of places in the UK (gatwick etc) if you didn't mind hopping over to london first.
if you are willing to go via the states there are always seat sales on aer lingus to nyc or newark. it's only about a 70 minute flight from new york city to toronto, and there are usually about 15 -20 flights a day to toronto from most nyc airports. the downside is that immigration and customs lines are usually long, but that's gonna be true for london transfers as well.