Who Should I Vote For In The US Election?

Yesterday, I received my absentee ballot for the US election.

I remain genuinely undecided as to who to vote for between Mitt Romney and Gary Johnson.

I was initially intending to vote for Gov. Johnson, however I am rather compelled by the argument that with 3 SCOTUS justices in all likelihood retiring  in the next presidential term, that this election has slightly some long-term ramifications in an area where I do believe Romney will be significantly better to President Obama.

On the Other hand… it is Romney.

So. Crowd-sourcing here. What should I do?

Potential relevant factor: I am registered in Virginia where the RCP Polling Average has Obama leading by just 0.4%.