Share your favourite spots in the GTA to listen to scanners.. low interference, etc. I can't seem to find many downtown spots that are close to the hwys and are Uniden friendly..
I woulds say Bluffer's Park would offer some good monitoring in the east of downtown core.
Any spot by Lake Ontario will give you a wide range of options.
If something came up that you wanted to shoot then you could easily drive west along Kingston Road or north Brimley from Bluffer's Park to the 401 and get to where you need to be.
I have family in Newcastle, Ontario and there I have been able to monitor Hamilton Public Safety (which I can't from Toronto); Rochester and Buffalo NY.; Durham Region;Toronto Public Safety except the West site. Fleetnet Zone 1 : Whitby,Pontypool and Fleetnet Zone 2 Cobourg.
This isn't really a public spot, but from an upper floor of a hotel in Oakville, I was able to reliably receive things from Toronto (probably further East, too, but I didn't really check) down to Ashtabula, OH, as well as NOAA weather radio from Central Pennsylvania.
Any location downtown and near highways will be subject to heavy cellular interference. Most on/off ramp areas are heavily saturated. Not exactly what your 246 likes to hear.
In the northeast, Steeles and Beare Road is reasonably high ground and the nearest cell sites are 2.5 km away. There is a good parking area on the southeast corner as well as on 11th Line just north of Steeles. The 401 is a quick trip down Beare and Meadowvale.
In the southwest, the southern tip of Lakefront Promenade Park has great reception - Peel, YRP, all 4 TPS zones, plus lots of VHF/UHF systems. It's a 4 km drive to Cawthra/QEW.