Vettel currently leads the world championship table by 10 points from the Spaniard with just two races left this season.
"Do I put Sebastian in the same category as Fernando? I don't," Hamilton told BBC Sport. "Fernando was my teammate; I know just how quick he is.
"Fernando didn't have the quickest car. Not a great car at the beginning of the year and he still managed to score some great points. Just massively consistent.
"You know that consistency I was talking about wanting to get? Well, he just toppled mine and kept going and going and going.
"He got taken out in Belgium, but the team have just not messed up. As a team they are the most deserving and Fernando has done a great job."
Hamilton was Alonso's teammate at McLaren in 2007.