Someone said early on that the important thing was to get the most competent person. I'd like to agree with that, but sadly, I don't think it's true.
If you look at Ed Miliband, the attacks on him by the right-wing press were rarely about his competence. They were much more about how "weird" he looked, his north London background, his refugee parents and his inability to eat a bacon sandwich. None of these were anything to do with his competence as a politician, and all contained an unspoken undercurrent of anti-semitism.
So it seems to me that, yes, you'd want someone who's competent, but also someone who looks pleasant, has a bland personal history and who appears personable. Tristram Hunt is too easily attacked for being posh and having an academic background. Yvette Cooper is too closely associated with the previous administration and it's a fair bet that the right-wing press would run with a "Vote Cooper, get Balls" line.
For me, none of the candidates stand out. I always liked Alan Johnson but he has said he won't stand. I do like Creasey - I don't know much about her politics but she has an aura of competence and likability. Chuka has the advantage of being good-looking - beyond that I don't know much about him, but I do think he may be a bit young for the job.