If you can get down several hours early, Real Sports is a great place to watch a Leafs game.
It is always packed though, which means that you'll probably want to get there a good 3-4 hours before puck drop. The atmosphere alone makes it worth it. If it's too busy, you can always try and find a bar-top somewhere and spread yourselves out - that's what we normally do.
Loose Moose and Jack Astors are my 2 personal favourites - always a good crowd and atmosphere in both and are all within walking distance of the Air Canada Center.
Jack Astors is just far enough that you are close enough to the ACC for game time, but just close enough that you can meet up with your family after the game without trying to look around amongst hundreds of other Leafs fans
Also - E11even is right next to Real Sports, and if your family is planning on eating that would definitely be the place to go; probably some of the best food in the area plus good viewing for the game as well.
So yes - if you want recommendations, it would probably be:
1 - Real Sports
2 - Loose Moose
3 - Jack Astors
4 - E11even
This is based on dozens upon dozens of Leafs games watched downtown. I do it once or twice a month, and I rarely venture outside of those 4 places because they are perfect for every sort of occasion I'm downtown for - birthday, date, family gathering, etc.