There are some sites but I don't remember those as I don't need to browse those but there are some issue with YouTube that Google still hasn't fixed. Chrome loads a different version of YouTube on Chromium browsers. One of downside of YouTube on Firefox is, on Chrome if you hover your mouse pointer to a video, it shows a brief preview of the video but it doesn't work on Firefox. At first the issue was related to Firefox as it didn't support Google's WebP image format but Firefox is supporting WebP for almost a full year now.
If you load in YouTube in Firefox, then change the user agent to Chrome and load another page of YouTube, you'll see that video preview option is working on Firefox. So, there's no compatibility issue and only Google is to blame here for their anti-consumer policy.