I don't change mobiles so frequently, although sometimes I would like to. My mobile history, to the best of my knowledge, is as follows:
Nokia 7250i - Around mid 2004, my first intro into the world of mobile phones..
Motorola E398 - Early 2007. Was a regular at howardforums to read about flashing this amazing phone.. It endured all my experiments until mid 2008, when it finally became a brick.
Nokia 5320 Xpressmusic - Q3 2008. Lasted until end of 2010. Was handed over to my wife, who used it until early 2013, when it started causing minor problems. I still have the mobile, and it works for basic calling and texting purposes.
ZTE Blade - Early 2011. Discovered this mobile here on TE. Lasted well until Q3 2013, when I stumbled upon another good deal here on TE. Had sold the Blade to a TE member, but unfortunately, the device was lost by the stupid courier people.
Nokia Lumia 520 - Sometime in Sep/Oct 2013. Bought the AT&T version from US for around 6k. Loved this mobile, until a freak accident in Dec 2013 broke it to pieces, literally.
Samsung Galaxy S Advance - Was bought sometime in early 2013 and used by my wife. After my Lumia broke, I have taken over this laggy mobile for some time.