Disclaimer: I am German and I actually saw and liked 30 Rock (in English) ;-) As for 30 Rock: The problem with English shows on German television is that they are all dubbed. I won't say that they are doing a bad job (c.f. eastern european countries) but sometimes they are missing out puns and jokes which "can't be translated" without losing meaning. In the end this can make a funny TV show unwatchable. On the other hand you will never (as in never ever) see an undubbed show on German television. People are used to watch it in German, so most of them might just never watch it again in either language.

edit: s/Disclaimer/FYI/