Probably the best chain of self-serve fro-yo in Montreal. I'm a big fan of Yeh and come here very often with my girlfriend. They often have new flavors of froyo (I have a soft spot for strawberry cheesecake, lychee and chocolate) as well as different toppings. The staff is very helpful and it's a cool place to hang out when it's nice outside.
The only reason it doesn't get more stars is because it doesn't compare to the US chains like Red Mango and Pinkberry.