They'd all been perfect in their own way, really. Just what he'd needed at a given moment in time.
Donna, who'd understood that his hearts were broken, and didn't try to push her way in, blunt in her offer of friendship, and nothing more.
Little Amy, her sweet, childish innocence the ideal balm for his soul after the final links to his home had been severed past all hope of recall.
And Clara. Sassy, and funny, and so pretty (even if he could never manage to say that bit out loud). She made him laugh. Such a simple concept, but oh, so necessary, even for thousand year old Time Lords. Perhaps especially thousand year old Time Lords.