Grass River - Mostly flat water with two ~1km portages and two 50m portages. Both of the longer portages are mandatory. With swiftwater sections before two of the portages, it's useful to know the basics of eddying in and out. Campsites are all on islands, and while unmarked, are generally easy to spot, except for the last one. Can be done in 48 hours, but more pleasant if given 72.
The first day will take you passed Kwasitchewan Falls, and the island campsite has a great view of them.