I assume you are already quite aware of...
Grizzly, Caribou, and Four Lakes Loop. I know you have been in Canyon Creek and up Stuart Fork.
Rush Creek Lakes is very nice. I have been there twice on summer weekends and seen no one else. To make a decently long hike of it, use the East Weaver Creek Trail.
Swift Creek is full of horse packers, but I really like the scenery from Mumford Meadow up to Horseshoe Lake at the right time of year.
North of Stoddard Lake, is a flat area covered by meadows, brooks and dense stands of conifers. I want to go back on the short trail in to Stoddard Cabin, and make a loop up to Doe and Granite Lake. Loop hike choices without crossing major drainages, yay!