I couldn't find a place to give feedback, so I'm just gonna write it here.
I want to order my issues by Priority, however I don't have that option.
It would be great if we could assign a Priority to our issues, and also arrange them based on that criteria.
Thanks for this feedback! We're always working to improve GitHub and the GitHub Community Forum, and we consider every suggestion we receive. I've logged your feature request in our internal feature request list. Though I can't guarantee anything or share a timeline for this, I can tell you that it's been shared with the appropriate teams for consideration.
One thing to note while you're waiting for the above is that you can probably achieve something pretty close to what you want with Labels and Projects. You can assign a priority to an issue via a label and then sort them into columns or in priority order in a project. I know it isn't as simple as what you're asking for, but you should be able to get it pretty close for now.
I hope that helps!
It would also be nice to be able to change the default view on the issues and PR tabs to take advantage of the sorting/filtering mechanisms available (including this new priority-based sort/filter option). The default sort mechanism assumes that users want to see the most recent issues on the top, which is quite often not what is most useful. This would allow repo admins to set the default views to be the most common way the tabs are used (i.e. higher priority items at the top so they get picked up sooner) so users don't have to keep changing the view filters/sorting. Currently, I'm leveraging milestones to replicate prioritization because issues assigned to a milestone are manually sortable. But devs forget to go look at the custom tabs I've created and just look at the issues list and without thinking pull the top-most issue that is not assigned to a developer.