Dishes: for me, doing and folding laundry as well. Like the dishes, its something that needs to get done on a fairly regular basis to keep the household going, doesn't require a whole lot of thinking, and its one of those "well, no matter what else is happening, at least I can do this" things, which can also be useful as a starter/catalyst to get going on certain days.

Vacuuming was another thing in this category for me until we switched to an robotic one. Fit into this category, it also makes the phenomena of compulsive vacuuming/cleaning by some a little less mysterious as just another ritual/habit.