Princess Auto (2802 Idylwyld Drive North) — Tools of all kinds and a handy surplus section. Careful with the Power Fist tools; they are often poor quality. Can be a good source for cheap parts.
Plastic
WD Plastics — For sheet plastics such as ABS, Acrylic, PETG (co-poly) for use in the laser, or HDPE for use on Goliath.
3D Printer Filament
The Makerbot uses 1.75mm PLA. The really cheap stuff doesn't work well.
B&E Electronics — B & E carries MG Chemicals. Our members have had good luck with this filament
Amazon — Amazon carries AMZ3D. Some of our members have reported good luck.
Digi-Key — Canadian mail-order supply for almost any parts imaginable. Prices are a bit higher than others.
Mouser Electronics — American-based business with a Canadian outlet. Larger selection than Digi-Key.
BG Micro — Surplus electronics. You can often find useful stuff for cheap, but some of it is just cheap.
SparkFun Electronics — Hobbyist electronics. Great for prototyping materials (Arduinos, shields, sensors, etc.). Prices are sometimes a bit high.
Seeed Studio — Chinese manufacturer of hobbyist electronics. Many open source hardware projects at extremely low prices. Also does custom PCB manufacturing.