If that truly is your only way, you're just going to watch what you fear would happen happen anyway.Democrats are evil. Republicans are evil. The only way to make that evilness not happen is to not vote for either of them!
If it's just 'fuck you both, I really don't care since you both suck, I have my principles', fine I guess, but to act like you're not putting yourself out of commission by (pressumably) voting third party is naive. This long con of ignoring the two party system has not made much of any headway. Not by just voting third party and hoping it'll stick eventually anyway.