Nexus 4. I got it on sale in fall of 2013 when they were trying to clear them out as the Nexus 5 launched. It's on its way out however...
Galaxy S3 (I9300) International, it was released in May 2012 so it's 5 years old in a few days, although I didn't get mine until August 2013. It's really struggling now though (1GB Ram and poor battery). I also use an Xperia U which was release Feb 2012, I don't remember when I got it but it must have been about a year before my S3. I'm using the Xperia U at the moment as the S3 battery life is ruined, it has 512mb ram so it's unusable for anything other than calls/texts/whatsapp, I can't use Chrome or do any web browsing it's pretty awful. I've just ordered a new phone though. Xiaomi Redmi Note 4 (SD) Global Edition w/ Band 20, it should come in a few weeks.
My s5 was 2.5 years old and still in perfect working condition but felt like a new toy so bought an s8 last Friday and wow what a difference.
Galaxy S3, so around 5 years. When the battery started giving in 2 years ago, I replaced it with a huge brick from Anker. It lasts 2 days minimum with heavy use and up to 4 days mostly idling. So far I haven't seen anything in newer phones that would justify the costly upgrade as long as this one works.
I recently upgraded from a Galaxy S6 to a Galaxy S8+. I usually upgrade every two years, and usually with a new contract, although I bought my current phone outright. I still have my S6 but the battery expanded to the point where the back and front of the phone are pulling away. Not sure if it's worth getting repaired.
Kept my Blackberry 9900 for almost 5 years switched to a S5 Neo in January.Don't need all the new features we''l see if this lasts 5 years too lol.
Still on my 1st smartphone, galaxy alpha bought it early 2015. Thinking about new for a while now, but there is nothing in such size or specifications. The only thing that really sucks is its battery, shame I didn't act fast enough and bought 2500mah extended kit. Ok it still has 4-5hrs ost, but i want moooar Maybe custom rom lineage 14 will do some magic, but I'll wait a bit until it gets more stable, would be nice to have at least Marshmallow 6, not this ****ty Lollipop 5.
Got two phones, one's a backup.....main phone is a pretty new (bought about a month back) LG G6 (64GB storage, 4GB RAM and HiFi Quad DAC). My backup phone is one I'd gotten about 17 months ago, it's a Sony Z5 Premium, sent for repair while it was still under warranty (microphone FUBAR'ed) and it's been going strong since.
LG G2 - 4 years old, absolute beast of a phone. Never had anything break on it. I'm running the latest Android 7.1.2 Release 8 with the May 5th security patch and Google Assistant, what more can I really want? Looking to upgrade to the new OnePlus which should hopefully last me a few more years, I just really want a bigger screen than 5.2" and longer battery life; a better night camera would be great too.
Moto G4, had since launch in 2016. Love the phone, and found my new daily distro for it. This is now my new daily device since my Pixel...Got smashed.=[
My iphone 4S has been with me for 3 years already while my Asus phone tablet for only a year and 6 months.
I'm on a Panasonic T44, after my Lumia made me pull my ears out. Its funny how sturdy this thing is, has fallen off / somersaulted on rocks while in the field and still is not giving up. I'm certain no one has even heard of this model, let alone see or own it xD. I'll be dropping this while on my bike trip if i get bored, but till then, this will do