The same lessons, year after year....
Had to laugh at how we sometimes get "trapped" into doing the same projects each year--though I personally love the idea of the moveable murals and the chairs (probably because I haven't done them!)
There are some things I intentionally repeat each year--the gridded self-portraits for Art I students, mainly because I feel it really pushes them to develop their drawing skills.
I'm not planning to do the self-expressive portrait masks this year (http://www.art-rageous.net/Self-ExpressiveMasks.html) and I know some kids are going to be disappointed. It's just time to give it a break and do something different.
What are some of the projects you feel "obligated" to do each year?