Banking accounts (anything that handles money) and your email account (usually used to confirm other accounts) are the important ones.
Next would be any subscription accounts (stuff you pay for), and shopping accounts. You may have saved credit card info on these accounts.
If you've filed taxes online or created accounts on any government websites, you should change those too to protect your identity. But the government is pretty good about enforcing 3-month or 1-year password changes on those accounts.
Finally, if you've got accounts controlling any assets (domain names, website hosting, etc), change those as well.
If you haven't yet, I strongly recommend enabling 2-factor authentication on all of the above accounts that you can. Install the Authy app on your phone (it requires a separate password or passcode every time you use it) instead of Google Authenticator (no separate password, so a thief who has access to your Google account on the phone can use your Authenticator). When you login to one of these accounts, you then have to take out your phone, start the App, and type a code generated by the app into the website in order to complete the login. Authy also synchronizes across multiple devices, so you're not screwed if you do lose your phone.
https/support.google.com/accounts/answer/185839?hl=en
https
/www.paypal.com/webapps/mpp/security/security-protections
https/www.amazon.com/gp/help/customer/display.html?nodeId=201962420
Do note that enabling 2FA also makes recovering the account much more difficult should you forget your Authy password, or lose your phone (if you use Authenticator). So make damn sure you protect those. Some sites let you create a few one-time-use passwords to access your account in case this happens. I recommend using that, printing out the codes, and storing them in a safe or safety deposit box.