Torres and Dirk Kuyt put Liverpool in front but Alessandro Diamanti, with a penalty, and Carlton Cole levelled. But Spain forward Torres head the winner in the 75th minute, delighting Benitez.
"If he continues to play like he did, he can be one of the best," said Benitez. "When you talk about the Premier League you talk about a lot of players with quality so it is not easy to pick just one, but he is among the best."
The victory, Liverpool's fourth successive win, lifted the Reds into third place in the table and left West Ham in 14th. Benitez also praised Kuyt and substitute Ryan Babel, who set up Torres' winner.
"We were in control of the game and the reaction of the team was very positive," said Benitez. "I could see that Kuyt was tired and Ryan was really good. His pace was crucial for us and the key at the end."
West Ham boss Gianfranco Zola admitted it was difficult to find an answer to Torres.
"He is a great striker, he is not easy to mark," said Zola. "It is not easy to defend against players like him especially when they are in the form he was in."
But Zola was more encouraged by West Ham's performance and promised they will soon improve.
"It was very encouraging," said Zola. "We were unfortunate not to pick up any points. But we will get better and it won't be long."
One of the successes for Zola, along with new-boy Diamanti, was the performance of winger Zavon Hines, saying: "The boy is taking his chances very well."