I got hooked on browsing openalternative.co is "Most Popular" list (openalternative.co)

This is an absolute gem in finding what are the trending state-of-the-art open source programs. I have found so many cool open source projects I feel addicted to browsing more..

there is also:

https://www.opensourcealternative.to/

A European based alternative with a mixed bag of open source and closed source

https://european-alternatives.eu/