The thing is, Nader is a really really poor candidate. BTW, he's not even running under the Green party, he's running as an independant.
People are always saying that "we need a third party, or multiple parties". Ideally, yes, we need more choices. But find me some competant parties who have their shit somewhat together. Vote however you want, but it seems like you're just trying to be different rather than looking at his political views and policies.