Same here. And 6 is iffy. The muppets ruined the ethos for me.
The Muppets were a bit over the top but I still enjoyed the movie. I went to those movies as a relaxing distraction and liked them, the first one especially because at that time the special effects were really good. They were fun movies.
The next three movies took themselves way too seriously and were horrendous. The PC content of the last episodes turned me off.