I would agree today but only because Brees and Rodgers are coming off their best years and Ben hasn't been healthy lately. Only a year or 2 ago I would have disagreed with you and I would have said that it was defensible that Ben was better than either Rodgers or Brees at that time.
Well, a year or two ago (more specifically: pre-2009) the top tier would have been Brady/Peyton, and it still would have been laughable to suggest that Ben was better than either one of them.
Notwithstanding the fact that injuries matter (otherwise, Peyton would already be back in the top tier), there was really never any point where you could legitimately call Ben the best QB in the league. He's never even received a single vote for NFL MVP. That says a lot.
I also can't say that next year I won't think that Ben is the best QB in the NFL again if he's healthy and those other 3 don't have the years they had last year. I'm more of a "What's his top level of play" type of guy when it comes to comparing them rather than a "Who's playing at the top level at this minute" type of guy because that changes from game to game and year to year.
I think Ben would need to have a 2009 Brees-type year just to insert himself into the discussion. As I just mentioned, he's never been anywhere near an MVP candidate, which distances him from the top three. Right now, the only thing on Ben's resume is team championships; he doesn't even have a SB MVP (and, in fact, literally turned in the worst performance of any SB-winning QB, ever).
Now,
could Ben turn in a season like Rodgers just did and catapult himself into the top tier discussion? Sure. He's close enough. But then again, so could Rivers or Vick. And that's how QBs progress from the second-tier to the first-tier.