Your favourite iPhone killers

People have been predicting devices which will put an end to the iPhone ever since it was created. Smartphones such as the original Samsung Galaxy S, Nokia N97, and even the iPhone itself have been listed as possible candidates in their own times, and more are surely on their way.Now that the 7th generation of the iPhone is almost at our doorsteps, probably accompanied by a new younger sibling, I think it's a good time to hear about your thoughts on iPhone killers past, present and future. Which one is your favorite?