My worst purchase ever is must be Redmi Note 2 of Xiaomi. There were lots of hype about how good this phone was, its battery life and speed. I asked a friend from China to get it for me as it was very expensive here. From the first day I got the phone, the battery was a crap, it didn't even run for 2 hours, the OS was awful with lots of Chinese inbuilt apps, although it was fast and lightweight. I used it for a month and gave it to my younger brother. From that day on, I am staying away from these Chinese branded phones.