Moved across to Android when the 5 was released as I didn't like the form factor (too long and narrow) and unlikely to move back again now, but will see what the 6 has to offer
iPhone
iPhone 3GS
iPhone 4
3x iPhone 5 (the first one had a faulty lock button after a couple of months, second had developed green lines on the display, etc.)
2x iPhone 5s (the display on the first one got shattered after seven days, bought a new one.. )
Though I did own two different iPhone 4's as I sold my AT&T 4 and switched to Verizon when it became available. Felt good to finally have the iPhone on a proper network.
Might get the 6 even though I usually don't see the point in upgrading from one generation to the next, but a family member is due an upgrade that she doesn't care about using, so I might use it to get a 6 and give her my 5s. She's already given me permission to do this, otherwise she'll just get whichever iPhone is offered for $0 when the 6 launches, which will probably be the 5c.