spronkey: Well... lets see if I can remember...
Nokia 252 in 1999
Nokia 5120i in 2001
Nokia 3315 in 2002
Nokia 7250 in 2003
Nokia 2280 in 2003
Sony w995 in 2009 (wow, big gap there... those two Nokias lasted me forever!)
Nokia 3210 Classic in 2009 (I hated the w995)
iPhone 4 in 2011
Nexus 5 in 2014
iPhone 5 in 2015
Of all the phones above, only the 3315 and Nexus 5 died. The 3315 dropped into a toilet, and the Nexus 5 I still have, but with a broken screen from a <30cm drop (sigh).
I stopped being able to justify spending more money on smartphones, and opted for a second hand iPhone 5, basically because my iPhone 4 was just too slow with iOS 7.
Interestingly the iPhone 5 came with iOS 6, which is so, so, so much faster than iOS 8 it isn't even funny. I wish you could downgrade, because I remember iOS 5 on my iPhone 4 being really usable, and really fast, for the things I use smartphone for (web, maps, twitter, email). Unfortunately on iOS it's difficult to stay far behind if you use e.g. banking apps, or productivity apps that cut off their older versions :(
Its intriguing how Apple ruin performance with OS upgrades, "encouraging" users to buy new hardware
And people come back for more
My iPad 2 is exactly the same, since the iOS8 upgrade I don't use it as its too slow
And I cant downgrade because, Apple...