Saw them live in Copenhagen last night (32000 people) and it was amazing. They still sing wonderful together, their voice matches do well, and we got to hear all our favorite songs. The Everly Brothers were guests, and sang 3 classic love songs from the 50s and 60s.
My favorite Simon & Garfunkel song is "Sound of Silence" - the live version is even better, the chorus on guitar sounds great.
http://www.simonandgarfunkel.com/