Realistically speaking, I don't think I'm willing to DIE for any right. I'm really interested in liberty in my lifetime. Now, there are ones I'd risk my life for, but if I knew that I'd die, I'd probably not pick that fight.
It's almost impossible for me to answer that question though, since the only think I consider a "right" is life, liberty and property and I consider them the same right, not a heirarchy.
"Self-ownership" would probably be the biggest spark. I'm already a member of the FSP, but if that passed in Janurary 2009, I think I'd just up and move right then. Of course, the "War" on drugs is essentially the same issue as is the ability to sell one's labor and own the tools of that labor...
So yeah, that's a really tough questions to answer since they're all so tightly enmeshed.