First of all, I don't agree that Hulk can be put into the "best drivers" category. Not yet. Yes, he's had a great season, but he wasn't exactly driving a truck and I believe he was very flattered by his rookie teammate. Many drivers show great potential in midfield cars and fail to deliver in top cars under the title pressure, so I'm not ready to consider him a top driver yet. Hulk had a chance to win a race last year and he blew it, so I have my doubts about his ability to deliver under pressure. Maldonado, whom everyone likes to ridicule on this forum, had his chance and he didn't blow it. Vettel, whose Monza 2008 win many people like to downplay, had his chance and didn't blow it, either. So I'll reserve my judgement on Hulk until I can see him in a top seat -- and I don't think he's entitled to a top seat. No one is.
The fact is, there were 4 open seats in 4 top teams this season(which is almost unheard of), and yet he was overlooked by McLaren, Red Bull, Ferrari and Lotus for one reason or another. Lotus' problems are obvious, but the other three teams were free to choose whoever they wished. And yet, McLaren and Red Bull clearly didn't consider him to be good enough to choose him over their junior drivers. Ferrari did consider him as their #2 driver instead of Massa, but didn't consider him--a young driver at his peak--a better prospect for the future than a 34-year old Kimi who will retire in a few years. Even Sauber turned him down. I would expect that if they thought he really was "outperforming the car," as many like to say, they would try to keep him, regardless of their financial problems--because WCC points mean money and if the driver was really making the difference, they would try to keep him. But they didn't and they would know better than anyone if Hulk was "outperforming" the car.
So 5 teams rejected him or didn't consider him at all for one reason or another. This honestly is quite baffling if he really is that good. Yes, all of them had their reasons, but if he were that good as he's hyped, I doubt he would be overlooked by all of them.
He is still quite young, though, and if he really is a top driver material, he will be in a top car, sooner or later.
To sum it up, I think best drivers are in the best cars. Hulk is good, but one of the best? We'll see.