I'd love to see an Ontario Line station within Ontario Place itself. With an Ontario Line station, the province could save money by building a smaller parking garage or eliminating the parking garage idea altogether for Ontario Place.
Ontario Place's original source of inspiration, the Expo 67 grounds at Parc Jean-Drapeau in Montreal, has a station within the park, so why not Ontario Place? The idea of building a subway station is more politically palatable for the electorate, too, than a parking garage in the hundreds of millions of dollars.