Its not that the first one set such a high bar, its just the sequels have just never captured the magic of the first one.
I'll still watch it, and eventually own it when it shows up at the used book store for 3 bucks.
The last movie I saw was completely by accident. The Simpson's Movie was on HBO this morning when I woke up and I was just too lazy to get out of bed and / or change the channel. Usually that part of the morning is reserved for Sports Center.