Back when Lake Ontario was pretty dirty, Cherry Beach was (as I recall) one of the cleaner beaches in Toronto, tucked away in a bay. But it was pretty sparse in its amenities. It's only in the last few years that the city has been trying to spruce it up, making it a nicer enclave from the industrial/portland areas that surround it.
The park/picnic area around the beach is nice, along the Martin Goodman Trail. But the parking area has still been under construction; there have been delays thanks to all the rain this summer. There've been horror stories about the $100+ parking tickets given out on weekends to beachgoers who can't find a legal spot--so transit or bikes are a good alternative if possible.
Once the improvements are finished and the landscaping grows in, Cherry Beach will definitely rate four stars here.