Silver Sensor. Available at Sears (around $40). Looks dorky (like right out of the old Lost in Space TV series), but I am able to get all available signals in my area, and the thing sits on a box in the attic above my garage (signal amplifier not necessary either) - and I live in a area with very mature and tall trees.
It took a few runs up and down the basement stairs to get it aimed just right, but once I found the sweet spot, I secured the antenna (to retain its position).
Signal comes in rock solid.