Toronto is just about the only place I would consider a mega city in Canada. However, you said you enjoyed the city so I don't know if its size is an issue for you.

If Toronto is too big for you, then your other good options for tech are in Montreal and Vancouver.

Montreal:

• 4 million people
• Housing is very cheap
• Lots of art, music, students, and drinking outdoors
• Best train system in Canada
• Summer is beautiful and hot (25 to 35 degrees and humid)
• Winter in Montreal is fucking hell (-20 to -30 degrees)
• Not knowing French makes it more difficult for you to integrate
• Taxes are high and most of that money is wasted due to corruption
• The city's architecture is beautiful in central neighborhoods (Plateau, Westmount, Outremont) but downtown and the rest of the city and its suburbs are very grey and depressing

Vancouver:

• 2.5 million people
• Unbelievable access to nature (mountains, beaches, forests all accessible by city transit)
• Growing transit system (train system is already larger than Toronto's in rail-length)
• Good services and taxes are alright by Canadian standards
• The city is clean and everything looks well-cared for
• Best quality seafood and fruits in major Canadian cities
• Mild climate (London temperatures but with 300 more hours of sunshine)
• It rains a lot in the winter. The city gets as much precipitation as Toronto and Montreal year-round but isn't as spread out
• Rent isn't that bad but buying a detached home is extremely expensive
• People are laid-back and outwardly friendly but take a while to become comfortable around you

Toronto is probably your best bet but otherwise I would suggest Vancouver. The tech scene is larger than Montreal and the economy is in overall better shape. Also, not knowing French puts you at a disadvantage in Montreal.