There's more than two parties to choose from. There's only two realistic choices because as a population you all choose to make it that way.
Don't get me wrong, the US isn't alone here. We have the same problem here in the UK. I usually vote for a third party that more aligns with my own views, not one of the main two, and people tell me I "wasted my vote". My response is: Did I waste my vote, or did you?
Simpsons of course parodied the situation best when the two aliens both ran for president.