Except for those shows filled with gasbags and bloviators on the cable news networks, there is no more immediately topical program on television than Comedy Central’s indefatigable animated wonder, South Park. Who could have imagined when it premiered 20 years ago that it would last as long as it has, get away with so many outrageous stories and become the go-to show for a comical and insightful take on current events? No subject is off limits. No topic is taboo. And no episode goes by without an “I can’t believe they did that” moment or three.