#8) ACF Fiorentina (40) 1955/56
Fiorentina won their first Scudetto (Italian Championship) in the 1955/56 season. They were so dominant that the side won the league with a 12-point lead over AC Milan at 2nd place. The side were so close to completing an unbeaten season. However, they were beaten in the final game of the season losing 1-3.
In all, the side registered a 40-match unbeaten run that would not be surpassed for another 36 years in the Italian league. Following this remarkable run, the side established among the elites of Italy with 4 consecutive 2nd place finishes.
#7) Chelsea FC (40) 2004/05
Jose Mourinho announced himself to the Premier League in the most remarkable of ways. He took over a cash injected Chelsea side and was tasked with winning the Premier League over the more established Arsenal and Manchester United.
His first loss came at the hands of Manchester City in the October of 2004. However, that would be the last time his side would lose a game for the next 12 months and 3 weeks. As a result, the Blues won their first ever Premier League.
Their unbeaten run finally came to an end with a loss to Manchester United in the 2005/06 campaign. Regardless, Mourinho engineered a second consecutive Premier League title to firmly establish Chelsea as a top Premier League contender for the seasons since.