Man, tough poll for me. Like most have said, it's great to see a band out enjoying themselves with the new material they have. But I did catch one show of theirs during kind of an "off years" tour, and it still has been one of the best SY shows of my life (around the equipment theft).
http://www.sonicyouth.com/mustang/cc/070899.html
The setlist was right up my alley. And as much as I hated their misfortune, as a fan, it was a total blast seeing a band forced to familiarize themselves with new equipment. Just something new and unique...
As far as setlists goes, I just remember constantly saying "Oh wow, they are playing THIS?!?!?" time after time during that show. Constantly overjoyed and blown away. More-so than I have during any album tour.