The section I love the most is 317 or 318 and you will want to sit as close as possible to the rail. The view is amazing; following the puck is easy on the top levels.
Other great sections are the Blues or the Gondola. The problem is that you can rarely get tickets for the Maple Leafs. But Raptors games are a pretty easy ticket to acquire. The Air Canada Centre itself has all the amenities you will find in the typical NHL arena, private suites, overpriced restaurants - except for Tim's as they have to keep their pricing standard as per company policy. Overall you better has some cash to spend when you get here for the Leafs.