Enjoyed Leroy roy's Grandfather's Clock. This is also a great site with many artists- also found Rhiannon Giddens from the Carolina Chocolate Drops - one of my favorite groups.
I accidently found a great song on YouTube - "Carolina In The Pines" - which I have never heard before - but I'm sure is a fairly popular Bluegrass song. It has a fast tempo - some nice chording and picking. The following link shows a jam session in which Rhonda Vincent joins in. I don't know who the musicans are but they play a mean banjo and some great guitar -
The next link is the same song but two guys in guitar - check out the fingerwork on the guitar player (left) - there are some great notes & picking at the bass-end of the guitar