I'm still using a 19 month old Samsung S2 on a 2 year contract. Have always loved the phone, dropped it loads of times and was still working well. After a year of ownership however the screen started to develop black lines and the phone started to crash a lot. Saying that though, Samsung are awesome in that they have a 2 year warranty, perfect for anyone on a long contract like myself! Gave them a call, they collected the phone, replaced the screen in a day and it was back with me in no time. And that was all free of charge! The crashing error was simply due to a dodgy battery, £4 later and it's working perfectly on the latest Android OS (which is awesome by the way). Phone is nearly 2.5 years old but I still love it! Can't wait to get an S4 come upgrade time (hopefully)