Where to camp in Ontario at the last minute

Maybe you're like me and you're not a great planner but you love camping and you want to try to get out at the last minute. So then, you might be asking yourself "where can I go to find a decent campsite without booking months in advance?". Well, to summarize from my reviews, the following are great backcountry spots, with a high probability that sites are available for the weekend of your choosing:

Bon Echo Park - Joeperry Lake
Algonquin Park - Cansibay Lake 
Kawartha Highlands - Buzzard Lake
Kawartha Highlands - Sucker Lake 

In case this isn't where you were headed, the following are a list of campgrounds with low peak-season occupancy rates, but not necessarily low peak-season awesomeness (no guarantee that some of these are devoid of awesomeness).  You'll find the 2011 occupancy rate in brackets next to the park name, as well as if this rate is increasing (+) or declining (-).

Central Zone - Bass Lake (60%), Mara (57%-), Mikisew  (43%-), McCrae Point (57%+), Sturgeon Bay (65%), Restoule (48%), Sibbald Point (54%)
Northeast - Kap-Kig-Iwan (4%), Missinaibi Lake (29%), Mississagi (33%-), Renee Brunelle (45%+), Tidewater (16%), Wakami Lake (35%), The Shoals (28%-)

Northwest - Macleod (44%+), Quetico (42%+), Rainbow Falls (40%+), Sioux Narrows (27%-)

Southeast - Darlington (49%+), Ferris (22%-), Rideau River (44%+), Voyageur (48%+), Silver Lake (48%+)

Southwest - Earl Rowe (54%+), Selkirk (54%), Wheatley (49%)

I imagine there are some hidden gems amongst these, including Mississagi, Wakami Lake, Quetico, and Renee Brunelle. The Northwestern parks, with their very low occupancy rates, will likely provide a decent site and excellent scenery, in addition to not being very crowded.  I've heard that Darlington has a great beach, but have to recommend against Restoule (so-so camping and not much scenery).