I'm a huge fan of a Sunnyside inter-modal station. If the DRL ran through there on the way to Dundas West, GO put a station there, and a streetcar hub was built, it would be very useful.
You could then terminate the Queen streetcar there, and the section west of it could terminate there as a new route (507?), recognizing the very different operating environments each side of the junction. People could then transfer onto the DRL to head North or Downtown, or transfer to GO. It would also mean that a Waterfront West LRT link to exhibition wouldn't be needed anymore.