+1 on Manitoulin Island, really nice ride. And once you arrive in Tobermory, it's an interesting place to stop of for a day or two if you can. You can go for a hike or take a boat to Flowerpot Island. Here's a website, just in case you're interested http://www.tobermory.org/page/home/Welcome

Then heading towards Toronto (to connect with Waterfront Trail http://www.waterfronttrail.org/trail.html), the area of Caledon, Belfountain, Orangeville, Mono is hilly but very picturesque.