I think beating Donaire was huge, but the Agbeko win doesn't do anything for him in my opinion. Agbeko has been a ghost and lost most of his last few fights, albeit to good competition.
Floyd's opponents weren't great but those were fights that fans wanted. Guerrero represented the come forward/pressure fighter with a good chin that people wanted to see, and Floyd embarrassed him. Canelo represented youth, power, size etc... and was embarrassed. And it was on the biggest stage in boxing. Floyd was masterful. Rigo won and he was impressive, but he wasn't unscathed.