Sections 102-103 and 113-114 are directly behind the nets at the Air Canada Centre. The first row in each of these sections is Row 5 and sitting in that row will give you the experience of being a goal judge as you'll be one of the first ones to know if a goal is scored. To take this experience to another level, sit on the west side in 113 or 114 to be on the side where the Leafs shoot twice.
If tickets in the first few rows are too expensive or if you want a better overall view, aim for seats near Row 20. They're closer to the ice than you think and they're usually available at a fraction of the price of the lowest rows. Additionally, you'll have the advantage of being close to the section tunnel and of being able to see over the glass and its partitions.