Would be cool if Sourceforts and Dodgeball Source were added to the weekly events on Saturdays. These are epic mods that shouldn't be dead
There really needs to be a content warning system, perhaps take some notes from how Mastodon (and the Fediverse in general) handles it. Then I could put a content warning on posts expressing frustrations with Steam crashing my computer under a content warning, so those who don't want to hear my angry comments regarding Steam can just not view it... and of course spoilers as well.
make a community about the REAL best valve game of all time, half life 2 deathmatch
Ricochet-styled colors for UI are beautiful. Please never remove them

The Meet the Madic trailer is one of the most viewed in gaming. I think it would be a good idea for the TF2 community, but especially the entire VALVe community, to join together to get the trailer to 100 million views. I don't know, I say, but TF2 has been a topic of conversation lately because of the SDK and source code issue.
It should be possible to add alt text to images, for accessibility, and the times when images don't load.

I feel like there should be more options regarding the Twitter bot that tweets out and links any popular posts from here stuff like opting out, or having it tag your account if you have it linked on your profile, stuff like that

What about perhaps an RSS or Atom feed for new posts?

Maybe add a way to see the progress made on videos, and the thumbnail/title, for us starving viewers. (Concept art was thrown together in 5 minutes ignore how bad it is)

profile link support for Artstation and Gamebanana would be really neat, if that's possible I believe a lot of artists and modders would appreciate it :)