The unorthodox fallacy: The proposition is radically contrary to traditional or culturally-normative beliefs, therefore it's true. One may think of a naive fundamentalist Christian assuming a rebellious streak after encountering the skeptical worldview of college professors or the general ethos of secular cultural.
The voluntarist fallacy: The proposition is strongly believed in therefore it's true. This fallacy may be more of a self-delusory stubbornness than anything else. For instance, as a child I strongly believed in the rapture (thanks Dad for introducing me to The Stand) and to me an unpremised belief, so long as I strongly believed, was enough to justify its truth. I think this fallacy is also prevalent in a lot political debate, where being a devotee to a set of opinions is enough to justify the truth of those opinions. Of course these beliefs are not totally unpremised but--in my experience--one's will can be deceptive when it is accompanied by the fervor of political allegiances, and sometimes merely its force is the true deciding factor of the conclusions we accept.