Obviously this is all my opinion, but this is what I think about who ‘deserves’ what number of championships:
I like Button- he’s possibly my favourite personality, and was originally my favourite driver. However, I do not think he will win another championship, and if he did it would exaggerate his talent. I think one is justified.
Although Hamilton is sometimes too aggressive, he deserves to be a multiple world champion. Probably triple champion or more. I think it’s a shame that Vettel will beat him to becoming a multiple champion, as I believe Hamilton may well be the fastest on the grid and, despite controversy, the best racer too.
Vettel is deserving of being a double world champion- whether he deserves more is a question I would save until I see his performance in a less dominant car. The only win of his I can remember that was in any was inspiring was his first. In comparison, Button’s wins are more often thrilling and spectacular performances, let alone Alonso’s and Hamilton’s.
Webber is a good driver- he proved last year to be better than I previously thought, but I seriously doubt he will win a championship, and I think that based on his current and past performances he doesn’t particularly deserve one. He his in my mind to Red Bull what David Coulthard was to McLaren (I never found Coulthard inspiring, strange considering I am normally patriotic, but admittedly I came into F1 at the end of his winning days).
Alonso deserves at least one more championship. He is often embroiled in controversy, and I don’t particularly like him, but to finish without winning another championship wouldn’t be justice to his talent.
I don’t consider Massa as capable of even winning races any more. To be honest I’ve never rated him. He will never emulate 2008, and then the main reason it came so close were what I believe to be dubious stewards decisions. He reminds me of how Sutil would perhaps perform in a competitive car.
Schumacher has won plenty enough already and doesn’t have the talent to win another. Although I rate Rosberg, I’m not sure I can picture him as a champion- maybe when he gets a car that can challenge, then things might change.