The top three contenders are likely:
'92 Blue Jays
'93 Blue Jays
The other 2 teams that are close are the '81 Expos and '85 Jays. They both came within one game of the World Series.
Here's how I rank them based on who would be most likely to win a 7 game playoff series:
1. 1992 Jays - Balanced offense, good defense and much better pitching than the '93 Jays.
2. 1994 Expos - The best defensive (and offensive?) outfield in Canadian mlb history. Also the best regular season winning percentage (.649) among these teams. Unfortunately, we didn't get a chance to see them in the playoffs.
3. 1993 Jays - The best offensive team Canadian mlb has seen. The pitching wasn't as deep as the '92 Jays.
4. 1985 Jays - The best Blue Jays winning percentage ever (.615).
5. 1981 Expos - Had some HOF's and near-HOF's. Perhaps some 'Bluebird Banter' members with more life experience can rank them better than me.