Our friend Scott has put together a list of the The Ten Greatest TV Appearances by Punk Rock Bands.. Among the entries are NOFX's appearance on ESPN, Iggy Pop on Tomorrow with Tom Snyder, Brendan Kelly/Michael Graves on the Daily Show, The Sex Pistols on the Today Show, New York Hardcore on Phil Donahue, Fear/Ian MacKaye on SNL and many others.
Scott has also helpfully added clips to each entry so you can see the appearance in question. You can check them out here.