Takumi was one of my favorite places for sushi when I lived on the northeast side of Madison. Portions are reasonable for the price, the atmosphere and waitstaff are quite pleasant, and the food's always been very tasty.
I primarily order nigiri or rolls, but friends have said that the bento boxes and donburi are quite good as well. It tends to get a bit busy at times, so if you're not a fan of cozy, you can always order your food for pickup as well!