This is the best video of Beethoven's Op. 131 string quartet in C # minor I could find, by the all-female Cavani Quartet from Cleveland Ohio. It's not quite first class playing, particularly the first violin strikes me as a bit raw occasionally, but getting to look at the performance compensates for some of this.
http://www.youtube.com/watch?v=FxUH4_7OxRA
http://www.youtube.com/watch?v=46WZrE8xm9A&NR=1
http://www.youtube.com/watch?v=ty7dk9UMdoo&NR=1