github
I would like, upon visiting github.com, to see a list of the repos that I watch. In a wide enough column to cope with long names that differ only towards the end. The repos that appear on the right seem to shift from repos that I have some involvement with to repos that I have no clue why they are there, omitting many of my watched repos.
Is there a trick?
See Deleting a repository, from Help.GitHub.
Go to the repo's Settings page
Scroll to the bottom of the page and click "Delete this repository"
Read the warnings and enter the name of the repository you want to delete
Click "I understand the consequences, delete this repository"
Deleting a public repo will leave the forks, but if it was private, then all its forks would also be deleted.
Repository Administration - Options - Settings - Default branch select-box
Change "master" to any (existing) branch
Best Answer
To change the list of repos showing in "Repositories you contribute to" you'll need to change your commit behaviour.
The "Repositories you contribute to" side box lists repos you've forked or have push access to (that belong to other users or organisations) with these ordering factors (based on observation):
Or you can add a browser extension, like Greasemonkey, that would target and blank that section/block via CSS or other targeting rule.
You can't otherwise customise or remove the box.
The list of watched repositories can be found under Watched Repositories, which shows as a tab after you click through to Notifications.