The Toronto Maple Leafs built their current team through the draft.
Members of the Toronto Maple Leafs who were drafted and developed by the team include Auston Matthews, Mitch Marner, William Nylander, Pierre Engvall, Morgan Rielly, Timothy Liljegren and Rasmus Sandin.
Outside of John Tavares, David Kampf, and TJ Brodie, the Leafs core/key/best players are mostly homegrown.
Less impressive is what the Leafs did in the years following their top picks. As has been well established, Mark Hunter was very, very bad at drafting and the Leafs have paid for it for years.
Had Hunter hit on anything in the 2015, 16 or 17 drafts, outside the first round, the Toronto Maple Leafs may have been much more successful over the last several years.