There were a few good things in episodes 4077 and 4078.
1 The best Global Grover segment of all, at least for me, was the one in 4077. Of course, it was the Global Grover segment where he showed us hos to make one of Puerto Rico's own musical instruments: the guiro.
2 Was surprised to see one of the old Consonant Sound Limericks in 4078, the one for V: Violin.
3 There's a reference in Elmo's World: Sleep to a show I used to watch. At the end of the TV portion of Elmo's World, the announcer says "Stay tuned for Supermarket Sleep and the 6 O'Clock Snooze."
Well, the first one's a pun of a game show called Supermarket Sweep that used to be aired on the Lifetime Network. Man, I miss those game shows.
Hope this helps and have a good day.