Although Alonso thinks it is too early to judge which of his rivals will challenge him the hardest in 2013, in terms of driving talent he has no doubts about who he thinks is the best.
"I do not know who will be my main opponent for this season, he who has the best team, with the best year in terms of preparation, luck, testing, all of these factors, will help a driver or team to come on top of others," he said.
"But as for strongest opponent, who is strongest driver? My answer is Hamilton. It was true last year, it was true this year.
"The strongest driver? It is a personal opinion, not political, not to make people think something. Who is the strongest opponent, the strongest driver on grid? Who is the one you have to keep an eye on? It is Hamilton - and it will still be Hamilton next year."
When asked why he did not think Vettel was the strongest driver after winning a third consecutive driver's championship, Alonso said: "I am not saying he is not the strongest driver.
"In 2011, there was a fantastic performance from him. It is true the car was much in front of everybody, they [Red Bull] were first and second consistently, and when the car is good you tend to relax in some races.
"But I remember difficult races in 2011 with wet/dry conditions, and he did not do any single mistake. So for sure in these three years there were moments when he was better than anybody else and he deserved these three championships."
Although Hamilton has played down his prospects for the season ahead as he undertakes a new challenge at Mercedes, Alonso thinks is unlikely the Briton will not win races.
"I am sure he will be able to win," he said. "He is a super good driver because he won every year with any car: he won in 2007 and 2008.
"In 2009 they started around two seconds off the pace with the McLaren, and Hamilton was able to win races – and it was the same in 2010.
"Last year also Nico [Rosberg] we saw winning in China with Mercedes. So with Hamilton he will be able to win more than one race."
Alonso also said that he has 'much more' confidence about Ferrari's potential for the title battle ahead, after ruling out the possibility of a start to the campaign as bad as last year.
The Spaniard helped Ferrari bounce back from a troubled pre-season testing programme in 2012 to take the title fight all the way to the final round in Brazil.
"I am more confident, no doubt," he said when asked by AUTOSPORT about his optimism for the season ahead.
"The rules are continuing more or less the same as last year in terms of aerodynamics. In the 2012 winter we changed completely the exhaust position compared to 2011, and it was a little bit of a guess what we found on the car.
"But this year everything should be much more normal and we are much more confident.
"We can be faster or slower [than the others] but not 1.5 or two seconds off the pace, because it was a record what we had last year. It is maybe impossible to be worse than last year, so I am confident."
Alonso believes that Ferrari will be better off in terms of its aerodynamic development because it has understood the Maranello wind tunnel correlation problems that marred its efforts last year, and has forced it to close the facility down for an upgrade.
He thinks that focusing all its efforts on using the Toyota wind tunnel in Cologne will be a positive.
"I think this decision should help us and gain consistency in the results we have," he said.
"An F1 team is extremely complex. Aerodynamics is one of the main components, and the wind tunnel as we have said more than once had some problems during the last season.
"We had a front wing that would give us two tenths of a second [in the tunnel]. We would keep testing it, bring it to the race track and then it would go even slower.
"There were times when what we were testing in the tunnel did not correspond to what would happen on the race track.
"So simply we remained a bit behind in the last few seasons. Starting from 2013, we hope we are the ones who will innovate and we will have good correlation between what we find in the wind tunnel and on the race track."
He added: "We have changed many things and not just the wind tunnel. We have been strengthened with new members in the team; we trust our technicians and we have total trust in the new arrivals in team, total trust on the heads and bosses.
"We must be focused on driving and both Felipe [Massa] and myself, we are sure more than in the past that this can be a bit better, both in terms of wind tunnel results and in terms of innovation.
"So we have to wait and see the result. From here to Australia there is still plenty of time."
Alonso added that he does not understand why Red Bull's Helmut Marko thinks that he is too involved in Formula 1's politics.
Marko suggested in a recent interview that Sebastian Vettel and Red Bull had gained an edge over Alonso in their title battle last year because they had shut themselves away from what he believed were political games played by their rival.
Speaking at Ferrari's Wrooom media event at Madonna di Campiglio on Thursday, Alonso said he was baffled by Marko's stance, especially because if Red Bull had not taken on board the comments, then why was it responding.
"I do not think I am very good at that," said Alonso about whether or not he was too political. "I simply drive cars.
"I was surprised by those statements, but I think they were simply statements a bit mixed up, a bit meaningless.
"They say that they did not listen and they did not speak. They were saying they were not being influenced by what we said, but it means they did listen or someone woke up at night and read the comments - because they had to calm down.
"They [Marko's comments] were a bit mixed up, without any real control. So I do not think we should pay too much attention to those statements."