This app was mentioned in 5 comments, with an average of 1.80 upvotes
If you want to pay, there is a great app called "Ringtones Complete"
https://play.google.com/store/apps/details?id=com.rcp.complete&hl=en
It's expensive but they have the biggest selection/highest quality in terms of original content.
RCP Ringtones is my favorite source of Ringtones and notification sounds that are useful in real world work settings.
I've used RCP for years. Best collection of elegant, high quality ringtones and notification sounds on Android IMO.
I use RCP Ringtones. Love it. RCP Ringtones