The Difference between the political parties are just stupid piddly unimportant things like abortion, the degree of welfare, religion in schools, and other really minor things that I can't even think of.
The similarities are massive and of much more importance: both want fiat money, both want a central bank, both enjoy the CIA and vast military operations, neither want to give the people at Guantanamo a fair trial, they both hate drugs, they both love regulation, they both want bi-partisanship, they both want bigger budgets.... i could go on.
... I will, Democrats made fun of bush's budget but are now spending 2 trillion in borrowed money, the wars are still raging, guantanamo's still open, there is still rampant regulations... yada yada yada. All of these things are bi-partisan issues.
The truth of the matter is that they both need each other. They need people to be pissed off at one group so that people will join with the other group. They disagree on very emotional issues to make everyone 'hate' the other group, thus forcing people into only one of two groups. Then, they both casually increase all the things that people 'agree' on - like inflation and bombing innocents in foreign lands.
The truth is that if you really want a choice, you have to go to Libertarians, the Green Party, the newly forming Tea Party, or one of the others.