Well, some ideas I've been mulling about:
The one I've thought the most on is a thesis on a "platform" of morality to build on. Basically, I'm saying that Ethical Egoism is the moral theory that everyone should use, to build off. The justification, I believe, lies in skepticism - you can't be sure anything exists other than yourself. And thus, you, yourself, ARE more important than everyone else, and you should morally think of yourself first, then add in your beliefs, and modify your own moral theory accordingly. But the underlying theory lies with Ethical Egoism. Basically a Moral meets Epistemology thesis.
Another one is an ideal government. This one is a bit more vague, but basically I argue that pure democracy is not the best government for human progress, that we have much more potential than we have realized (well, obviously), and that we can accomplish much more if under one absolute ruler. The problem lies in if the absolute ruler is not benevolent, what then? That's what this thesis discusses.
I enjoy Metaphysics, and have thought about writing a paper on why Christianity, through Augustine and Aquinas and others, is appliable to metaphysics, and how it all works. Basically, the idea is to provide a philosophical view on how heaven and hell works, and why Jesus saved us all. This one would require me to play devil's advocate, since I reject Christianity as an religion. Can still be interesting, though.
Finally, on pure metaphysics, this one can be fun, but I'm afraid to visit this territory, because I can essentially pull **** out of my ass, and call it metaphysics - such as arguing that there is a giant teddy bear in the sky ruling over us.
Hope this helps.