This will depend on what services you need and want. If you want a no-fee chequing account, your only option between the two is Tangerine. If you want to trade stocks for free, Wealthsimple offers this service and Tangerine doesn’t.
Tangerine mainly provides banking services and credit cards (along with low-cost mutual funds) while Wealthsimple primarily offers investment services but also has a high-interest savings account.
You’re likely going to need both depending on your financial goals unless you choose a larger financial institution where you can get both banking and investing services.