Well, obviously Willowood would be right in Amherstburg, but I've heard it's really gone downhill since being a Jellystone, and it wasn't that great of a Jellystone to begin with. Did the first trip with our TT there 5 years ago.
Nearby is Wildwood Golf and RV. Clean park, but too stuck-up for my taste. For example, the pool is for seasonal residents only, transients not allowed. One thing it does have going for it is their transient sites were facing pull-throughs. If you're travelling with a friend, you can share a campsite. The downside is, if you're not travelling with a friend, you share a campsite.
I haven't done Winsdor Campground yet (the old KOA), so no opinion there. DW's heard enough stories though to not be willing to try it out.
After that, you start getting a lot farther out of the area. Next closest one would probably be Pleasant Valley Campground, near Kingsville:
Home - Pleasant Valley Campground
It doesn't show up on a lot of the sites like allstays or rvparkreviews, so it's hard to come by. Older park, but again clean and decent. I'd be willing to stay again but DW's still in the searching new parks mode.
And since I've gone this far, might was well run down the rest of Essex County and nearby:
Rochester Place: Haven't Stayed at yet.
Leisure Lake: Nice place, clean, would stay again. Beware of their 'pull-through' sites, there's no room to manoeuvre your rig 'through' just the tow vehicle. You have to back out of the site when leaving.
Sturgeon Woods: Nice pool setup, but a real lack of parental control of the kids on site has turned me off returning. I shouldn't be seeing 5 and 6 year olds out by themselves at 11:00 at night running in front of my truck.
Holiday Harbour: Another one that doesn't show up on a lot of the search sites, small park, older, and about 1/2 is mobile homes, but the transient sites (non sewered) are right on the beach, which is a plus. Clean enough that I'd be willing to stay again, but being on a beach, there is a lot of sand to deal with. The dump station is a little odd though with you pointing down a dead-end road. You'd have to back out of it.
Camper's Cove: Older Park, very clean, very friendly, no pool, but it's right on the lake so you can go in the water there if you wish. It's well treed so it's got a bit more of a 'camping' feel to it than some of the open field type parks. We usually do trips here twice a year. I'll open in the beginning of May, and we have an annual site on their halloween weekend in September. If I ever go seasonal, this one's the one that's high on the list.
And then finally, one that I'm not sure if it qualifies for a campsite or not:
Holiday Beach Conservation Area: They list it has having seasonal sites, but there seems to be no information about camping. I've camped there in tents way back in high school days with the Venturers (teen-aged scouts), but it doesn't seem like there's a way to camp there now unless you were one of the grandfathered seasonal sites.
Hope this helps,