There is just so much.
- Photography is doing quite well here, but it could do even better with a platform of its own. That way you wouldn't just be upvoting posts with good photography in them, you could be voting for the photographs themselves.
- Animation open source software similar to Blender where we can not just vote for quality 3D animations, but actually buy them from eachother for use in our own animations
- Music! Somebody here (I don't remember who) once suggested steemit could be a great platform for buskers. I think we could do even better than that by having a steem platform for all kinds of self-made music! This could solve the problem many artists have with piracy! You could simply vote for it in order to download it!
- The same thing could be done with movies where once you've watched it if you like it you give it your vote
- Commerce would obviously do really well, not only can you send your steem dollars to purchase lets say a new camera or something, but you could also give it your upvote as part of a review
- A Twitter like platform would be nice to filter out the memes here
And of course what you've already listed, crowdfunding, livestreaming, questions and answers even educational platforms, on which professionals upload teaching content and everything is categorised by subject so it's easy to find!