Used to use those types of sites a lot -- ie Newgrounds and Miniclip mainly for browser games but some of the videos are pretty funny too

Any other websites with similar content worthwhile checking out?

This might be of interest to you:
https://bluemaxima.org/flashpoint/

They preserved tens of thousands of flash games and thousands of animations that all ran on Flash.

And as far as I know, Weebl's Stuff is still around, making.... stuff.

https://www.youtube.com/c/Weeblsstuffpage

Badger, Badger, Badger, Badger, Badger MUSHROOM MUSHROOM... IT'S A SNAAAAAAKE