x3 on LSPP. The Orphan Lake trail is an excellent hike. (There are other easier hikes too.) Old Woman Bay is also spectacular.
I also like Pancake Bay for short stays. Be sure and get a site close to the lake (better views and substantially fewer mosquitoes), which can mean making reservations early. Also, sites with electric typically have a single post that serves two adjacent sites. That can mean quite a long cable run if you get unlucky. This seems to be true at most Ontario PPs.
Showers are available at both, and the bathhouses are decent. (At least they were when we were last there 3 years ago. :) )