I've had 3 - an old iPhone 3G that my dad gave to me, then an iPhone 3GS, and currently an iPhone 4S.
The way I got the 3GS was quite a fluke. I went into the Genius Bar because my 3G was about to die. When they looked in the drawer for a replacement, the only one they had had a jammed SIM tray. So they said, "We'll just go ahead and give you a free upgrade to the iPhone 3GS." I was overjoyed! I mean, what are the chances of that? This was in April of 2011, so I was happy I finally had a device that could run iOS 4 well.
Then I got an iPhone 4S in December of 2011 for my birthday.
I've had an iPhone for almost two years now and will never look back!