Android vs BlackBerry: Hardware
While all smartphones, including Android and BlackBerry devices, have a lot of similarities, one of the largest differences between Android and BlackBerry devices is in the physical phones themselves. Since BlackBerry devices are all made by one company, at any given time there are five or six active series of devices that you can choose from. A few of these series have devices that look and perform similarly, leaving you with only three or four real choices. Android, however, is an open operating system, meaning that many manufacturers can create Android devices. This means that Android has, at any time, dozens of different active designs from numerous different handset manufacturers. You are far more likely to find a device that fits your personal preferences under the Android umbrella than you are looking at BlackBerry devices.
However, there is a flip side to this argument. Since RIM produces all the BlackBerry devices, the quality is fairly similar and after some hiccups in 2008, almost all of the current BlackBerry devices have excellent quality. With Android devices, you are generally alright if you stick to major manufacturers like Samsung and HTC, but after that there is a wide range of device quality, and it will only get worse as the OS gets more popular.
For me, diversity is king, but I can understand the other side of the argument so we'll call the first category in this battle of Android vs BlackBerry a tie.