The 1966 Toronto Master Plan would have implement a grand scheme of both expressways & subways. Here's a detailed map of what was finished, proposed, and demolished.
Toronto IMO shit the bed by attempting the Spadina Expressway before any of more essential freeways. Metro Toronto caved to Cadillac Fairview who were screaming their tits off about how they wouldn't build Yorkdale Mall unless it was adjacent to an expressway.
IMO Toronto should have completed the 400 South to the Gardiner, and completed the Eastern Gardiner (Scarborough Expressway) to the 401. The 400 South would have been a perfect bookend like 404 & DVP are, and the Scarborough Expressway would have formed a nice ring on the Southern lake shore.
Spadina was the least desirable of all the Expressways, as it abruptly would have ended at Bloor and flooded traffic in downtown. Crosstown would have been alright but extremely expensive for such a short expressway, and Richview would have possibly negated having a collector-express system.
Moving forward, as much as public transit is vital to relieving commute times, expressways need to be re-visited also. The closest thing I've seen is from
http://www.gettorontomoving.ca/
This is what they propose for freeway and roads for Toronto. Basically finish the 400 South using the ROW only Black Creek Drive and the remainder under GO Rail lines to Fort York. Use the Hydro Corridor in Scarborough to build another freeway through there. It avoids the nastiness of expropriation as most of the land is owned, and gives real relief to the clogged GTA area freeways.