Which is better.iPhone 4, 4s, or 5?

So with all these ugrades we're getting through Verizon and such. I'm going to get a new phone- either the iPhone 4, 4s, or 5 and I have heard that the 4s is having some problems i don't know.
But heres the deal.
its free to get the 4 (plus $30 for the upg.)
$50 to get the 4s (plus $30 for the upg.)
$100 to get the 5 (plus$30)

On top of that my dad has some sort of theory that I also should pay for the phone itself because i don't know haha but anyway its going to be around $180 in total for the 4, $250 for the 4s, and $330 for the 5.
And with the iphone 5 being such a great deal i don't know but I don't want to spend all of that money to get a phone that's barely better than the first two.
Is the 5 really worth the money?
Which one should I get?

I would get the 5, But then again i would take the Galaxy s4 over the iphone any day of the week.

Depending on weather u care about a few more megapixels in the camera and a slightly faster processor and a very slightly bigger screen then go for the five but if you don't need that then go for the 4S definitely not the 4 really slow and old released 2010