In addition to the three finalists, there were a good deal of entries in the Orange Tree Samples Demo Contest that I thought were superb. One of them has an infectious riff that I absolutely love. The musician who submitted it was kind enough to share it after my request.
The song, called "Gun Slinger," uses Orange Tree Samples' Lap Steel Guitar along with live acoustic guitar. His acoustic guitar is a bit out of tune, which gives the song an authentic, old time blues recording kind of quality. The riff is killer -- I love it. I've played this tune at least 30 times since I first heard it. Give it a listen. The riff I'm referring to doesn't kick in until around 47 seconds into the song. You'll know it when you hear it.
https://soundcloud.com/christian-yoder/gunslinger