I've been checking out these older SIM (Center for Improvised Music) videos online from this vimeo page. There's also some great Curtis Hasselbring videos, Mark Helias and Ben Monder videos that are all high quality incredible live performances.
THIS is the link to just one of the videos, but scroll through the 50+ videos on the side to watch all the above mentioned ones. I'm slowly going through most of em, and some of the groups are just incredible. Tim Berne, Matt Mitchell, Tom Rainey, Drew Gress and Ralph Allessi...damn!
EDIT: I would also like to add some older Bloodcount videos that I found recently as well, which can be found HERE.
EDIT no. 2: ALSO like to add the Roulette TV Vimeo link to 60+ videos of Christian Wolff, Joey Baron, Robert Black, Christian Marclay, Henry Threadgill, etc... Check it out HERE!
Also side note, on a Morton Feldman kick right now, and have been listening to "For Bunita Marcus" and "For Christian Wolff." Feldman wins everytime, especially his late period long form compositions. I'm planning on a protools-multitrack "Projections-esque" piece involving all the instruments I have collected over the past few years that is a tribute piece to Feldman. More on that later!