By almost all accounts, the Toronto Raptors and Boston Celtics are the top two teams in the Eastern Conference.
Both teams finished atop the regular season standings last year, saw their biggest conference rival (LeBron James) head to the Western Conference, AND significantly improved their team during the offseason.
The Toronto Raptors improved via the Kawhi Leonard trade. Leonard gives the Toronto Raptors their first real superstar since Chris Bosh, and if healthy, the best player in the Eastern Conference.
The Boston Celtics improved merely from the passage of time.