If I had to pick just one place to go grocery shopping, it would definitely be Adonis. I find the fruits and veggies to be fresh and cheap and I can find a greater variety of them than at "regular" stores, grains and beans are way cheaper (think quinoa and wild rice here).
Mind you, driving there is a adventure on its own... Seems like people forget all about courtesy and manners when it comes to a parking space. Same goes in the aisles. You'll encounter -plenty- of abandoned carts in the middle of the way while the owner shops the other way, no cares in the world. Arm yourself with patience!
Note: Adonis Sauve does NOT accept credit cards. Not sure about the other stores though