2nd to #10.
For cheap options, try
http://www.hotwire.com/
Airport hotel with free airport shuttle as low as 50s.
The next morning you have the option to:
-come back to the airport to catch TTC bus+sub at $2.75 (exact change only). total 80min.
-come back to the airport to catch Airport Express at $18. total 60-80min.
-take taxi to Kipling stn ~$30 to catch TTC sub $2.75. total 60min.
-take taxi to Union Station ~$50. total 30min-60min.