Can't think of any to add to the ones here – most of those I've enjoyed most have already been mentioned.
Rosedale Valley Road in particular was a ton of fun the one time I tried it – not only pretty, but long, winding, all downhill, and with no stops! However, I wasn't really expecting to get dumped out onto a multi-lane highway – my (mis-)reading of the Toronto Cycling Map had made me think I could avoid Bayview and end up in Winchester Park, but if there was an opportunity to escape before Bayview, I clearly missed it.
Frank, I'm curious about two things in the route you listed – you seem to have ended up going north on Bayview? I got dumped out into Bayview southbound, and there didn't seem to be any way to get turned around – however, I was riding after dark, and wasn't expecting to end up Bayview at all, so I may have missed something due to lessened visibility and/or oh-god-oh-god-I'm-going-to-die nerves.
Also – you said there was a bike trail on Bayview? I didn't see anything like that, but maybe it's only the northbound side?