Apple TV or Roku: Which Media Streamer Do You Use?

We know News Corp is sinking a whole bunch of money into Roku, thus upping the stakes of the streaming media box war that's brewing amongst companies such as Apple, Boxee, Western Digital, Microsoft and Sony. While all the boxes are similar, each has its own strengths and weaknesses, . Which one do you use? Which one do you think has the best shot at conquering streaming TV?