I once swore that I would never use any other phone bar Nokia. If you can use 1 Nokia then you can use them all. Then the iphone came out.......I got the original and have never looked back. originally I made sure I had the covers on the glass, kept it in a cover and looked after it and it never missed a beat. Then I gave up on the covers etc, now the screen is scratched and it has a crack from the top edge to the ear piece, you can't even read anything on the back but it is still going strong. The battery is still good.
The thing you need to remember is all smart touch screen phones are based on the Iphone. The others stick a gadget on here and there extra but they will always be one step behind Apple. Everything with the iphone is done by Apple, hardware,software, itunes.....everything. The others have a phone based on reverse engineered technology, another company does the software then another company does the hardware. Apple is one of the largest companies in the world with pretty good back up service and warranty they build the phones and run the apps, the others use Android...a separate company.
Just remember that an iphone is a continued progression of the original ipod, a technology that has been tried and tested over years. All the back ups are in place and been running for years. The others are just pups in comparison. The reason most apps come out for the iphone first.....Tried, tested and popular. All the other companies, together, wouldn't have as many sales as Apple with the smart/touch screen phones.
Wait for the iPhone5 and then make your decision.