1. Toronto Maple Leafs
Existing Talent
Forward: Mitch Marner had 44 points in 18 playoff games in the OHL last year; that was on the heels of a second consecutive 100-plus point season. William Nylander scored at a better than point-per-game pace in the AHL and didn't look out of place during a 22-game major league cameo. They are the two best forwards in the system, but they head up a pool that includes Kasperi Kapanen, Frederik Gauthier, Connor Brown, Brenden Leipsic, Tobias Lindberg and others.
Defence: KHL All-Star Nikita Zaitsev is a nice addition to a defence group that is decidedly overshadowed by the forwards. Even so, Stuart Percy, Rinat Valiev, Travis Dermott and Andrew Nielsen (who had a spectacular year) ensure there's talent to come on the blue line as well.
Goal: College free agent Kasimir Kaskisuo bolstered a system that already included the rapidly improving Garret Sparks and competent AHLer Antoine Bibeau.
2016 Draft Additions
Auston Matthews is almost unanimously acknowledged as the best player in the 2016 draft, a slick, mature two-way centre with top-line offensive ability. He has NHL size (6'2", 210 pounds) and experience playing the pro game; he will almost certainly jump to the major league immediately.
The Toronto Maple Leafs' draft didn't end with the first overall pick, though. They made seven of the first 101 selections, stockpiling prospects at all positions. The list is too long to go through individually, but we should at least highlight No. 31 pick Yegor Korshkov, a 6'3" winger who was passed over in two previous drafts but had a strong campaign in the KHL.
Summary
No other team in the NHL can rival the collection of talent the Leafs have in the system.