1. Because I'm compulsive
2. Because a little bigger screen is all I ever wanted more on an iPhone since the 4.
3. Redesign is beautiful - being thinner and lighter is a plus I certainly won't dislike.
4. Faster... though the 4S was quite enough in any aspect of its use, I think 1GB of RAM is just gonna give the 5 that instant response in animation that's gonna be awesome on iOS...
Frankly, enumerating reasons why I get it is redundant. What I really have to offer is this : turn this the other side. Give me a single reason why I should NOT get it if I can?