I bought the very first android phone, the T-Mobile G1 aka HTC Dream in 2009 and run Cyanogenmod on it for years. Since december I have Android 2.3.7 and it works perfectly, except being slow on certain tasks. Even the battery life is quite ok. I'm still looking for a new phone though, but until now I haven't found one that really matches the G1s features (e.g. hardware keyboard) at an affordable price, so I'll probably keep it for another 6 months or so until it finally retires.