I'm biased towards android because I like the way it works better, but if you're apple/mac folk you will likely prefer the iphone. Everyone else in my family (wife and older kids) have iphones and love them. I will say they always work and they love them. They're also all mac users, so the similarities suit them. I have a LITTLE programming in my background and am a "tinkerer" by nature (I gues most TBNrs probably are), so apple product have annoyed me for years... I just can't get under the hood, and if I don't like the way an apple product works, well tough. With android, I can get dirty and see what's happening and, if I choose, make tweaks. It functionally seems more pc-like (it has, for example, a file explorer ao I can look around the phone "storage" as if it were a pc hard drive to see what I'm storing and add, transfwr, or delete files... I think newer iphones have some of this ability now, its just less intuitive). Among the greatest advantages of many (not all) android phones is their ability to use an sd card (actually a mini or micro sd), so you have expandable storage that can also be moved from phone to phone to tablet to pc to camera, if you wish. The downside is that android may be a bit less stable due to more options and flexibility.
I had the Samsung S2, now have the Samsung Note2. The Note is, by far, the best phone I've ever had... love the huge screen (great for my aging eyes... this is my other beef with iphones, screens are too small), best battery life and smoothest operating smartphone (all facets - calls, email, internet, dropbox, music, etc.). The Note2 is essentially the same as the s3, just larger. The S2 was the s3 predecessor, and also a great phone- I only replaced it for size. I think Samsung makes the best phones on the market today, bar none incl. Apple.
If you decide on an android phone, don't just drop an itunes clone on it... I left itunes behind with my first android phone and have never been happier. I now have music that is much more easily transportable phone to phone, computer to computer, or streaming from the cloud. Amazon is a great source if you buy music online, and you're never limited by apple's atupid device restrictions.