[rschmitty]

Since you said a great desktop interface.. check out MS OneNote, integrates with Outlook for schedule/reminders, very good drag/drop support of anything.

If you can pay $, Atlassian JIRA is the best for programming, you can schedule/plan tasks, get reminders, much better sorting of issues/categories, phases, have them automatically close with commits (JIRA is just like github only way more advanced in what you can do)

Now if you are doing an open source project for the community then hands down stay on github