I came across this site so I thought I would share, it’s quite fun especially if you have some time to spend Basically you keep picking Pokemon until you have a list of your favorites and the list is created by your choices. The site has good introduction for it too, it’s better to always pick at least one Pokemon than skip a group of them.
You can choose how many favorite Pokemon to display and you can also choose if you want to include forms, such as Alolan Forms and Megas. I included both but decided to ignore to megas to not “corrupt” my favorites list. I wanted to include the Alolan Forms on mine as they are different enough to be like a different Pokemon.
Here is my top 20 favorites, you can share yours too:
The site creates a link you can share but I went and took a print to show an example how it looks like