In addition to reasons already stated above, threads like this are pointless if you don't tell us what you want/need. Selecting a smartphone (like buying most things in life) is a matter of finding what suits you best. Without giving us your criteria you're only going to get responses from fanboys who are going to, of course, recommend what they're using.
Make a list of your priorities, assign them weights, compare the specs/features on the phones and you'll have the tools you need to select one. Add in trying them out in person (where possible).
