My mother absolutely adored Super Grover (well, Grover in general), as well as Telly Monster and Herry Monster.
I like this clip a lot, because I love how the little girl really doesn't need Super Grover. Super Grover is just in the way, mucking things up. And the little girl, after moments of panic, thinks out a workable plan and then moves to implement it. She's just foiled by Super Grover and his Hero Complex!
I kind of wonder where Super Grover changes now, though, that there aren't many telephone booths outside of Woodstock, New York.