What's the best cash back credit card in Canada?

Rewards:
Welcome offer: Get up to 10% cash back  in your first 3 months and the $120 annual fee waived in the first year*
Get the highest cash back earn rate on groceries in Canada.*
Get valuable benefits and offers for digital everyday services from a variety of on-demand apps and subscription services
Complimentary membership in Mastercard Airport Experiences provided by LoungeKey*

Rewards:
In your first 10 months as a new SimplyCash® Card from American Express Cardmember, you can earn a $10 statement credit for each monthly billing period in which you spend $300 in purchases on your Card. This could add up to $100 in statement credits in the first 10 months
Earn accelerated earn rates on eligible gas and grocery purchases
Earn 2% cash back on eligible gas purchases in Canada, 2% cash back on eligible grocery purchases in Canada (up to $300 cash back annually), and 1.25% cash back on all other eligible purchases

Rewards:
In your first 10 months as a new SimplyCash® Card from American Express Cardmember, you can earn a $10 statement credit for each monthly billing period in which you spend $300 in purchases on your Card. This could add up to $100 in statement credits in the first 10 months
Earn accelerated earn rates on eligible gas and grocery purchases
Earn 2% cash back on eligible gas purchases in Canada, 2% cash back on eligible grocery purchases in Canada (up to $300 cash back annually), and 1.25% cash back on all other eligible purchases

Rewards:
Welcome offer: Get up to 5% cash back in your first 3 months*
Then get 3% cash back on grocery purchases, 1% cash back on recurring bill payments and 0.5% unlimited cash back on all other purchases!*
Now earn the highest cash back on groceries in Canada without paying an annual fee!†
Get a 0.99% introductory interest rate on Balance Transfers for 9 months, 2% fee applies to balance amounts transferred*