Thats just it though. Southpark will never run out of episode ideas because they use real news.
Family Guy and The Simpsons use character conflicts in the show. Unless you add new characters every episode, you will run out of ideas.
And finally I disagree. If you think family guy isn't funny anymore, you're broken.
The new episodes rock. At first, there was to much funny in each episode, and it took a good amount of time to get used to it. Now, its the best that is has ever been. Southpark isn't haha funny, but more, thats so true funny.
SheepStar