Trans Canada Highway

Well the Trans Canada is probably the best way to get from one end of the country to the other, very flat across the Prairies, hilly in Northern Ontario mostly 2 lane and some roadworks, but its a beautiful drive up around the northern Great Lakes although you might have to get off it to see the better sights . Most of the Provincial Parks are a way's off of the Trans Canada more so in Ontario. Price of fuel gets high in the more remote areas where you don't have choice of stations. Its not like the U.S interstates with the big truck stops every few miles. The Northern way via Ottawa is mostly trees and lakes and Canadian shield If you go that way Algonquin Provincial Park is one of the best in the Ontario Parks system. Then up past North Bay up to new Liskeard & Hailybury there are some nice smaller Provincial Parks up that way right on the road like Marten River P.P and Finlayson Point P.P but the sites can be small. Then it goes on up to the true North then East. If you go the southern route it takes you through Peterborough and several smaller towns Hwy 7 is much improved now, then it connects to Hwy 69 & up to 17 and takes you up past the Great lakes. Killbear and Killarney are both great parks along the way as well although Killarney is well off the beaten track. Cottage country in Ontario is beautiful & loads of lakes. The Kawarthas The Muskokas, Halliburton & Bracebridge are part of it. The Park system gets very busy in the summer and you may not get in on a weekend unless you book well ahead but during the week they are usually not busy. The Northern parks aren't as busy until peak season and long weekends. Its worth the trip but Ontario is a huge Province so allow plenty of time to get through it
But unless you have a real need to go to Toronto I wouldn't detour there, the traffic on the 401 & going through the 6 is unbelievable at rush hour with major roadworks in the East end.