Although the time travel episode in Season 4 was funny at least.
wait, they actually did a time travel episode? I thought the creators said that they would never do it, both because Morty and Rick started off as Back to the Future parody characters and also since time travel plots rarely made sense when you truly began to think about. Closest thing was the S2 premiere where time was just frozen but not travelled through. They even had a visual gag with some stuff in a box in the garage being "time travel stuff".
Man, they cant even maintain that basic level of integrity