Wow, that's a very good question. It's definitely something that can't be answered simply in my opinion. Of course my natural knee-jerk reaction is to say freedom of speech. However, in order to protect any other rights we have, what good does freedom of speech really do? Of course you'd be free to tell people how you really felt, but if you're under the thumb of a new militant regime who'd just as soon shoot you as change their policies based on a public demonstration of the people, then what use is it?
I suppose it depends entirely on the current state of affairs for the nation. If it was a situation where politicians actually listened to the people rather than making decisions in the best interests of whomever donated the most campaign money then maybe freedom of speech would be the best choice. However, if the government wouldn't listen to the people in the first place, you may have to force them to listen to something, and gun shots are pretty loud.
Being a bit jaded at the moment, I'm going to vote for the right to bear arms.