I think there all good, but I like Simon Pegg, just cause I've been of fan of his since Spaced.
Chekov took a bit getting used to, but I got used to the accent.
John Cho was great, though at first I just couldn't get the image of Harold from Harold and Kumar out of my head.
Urban-perfect, he just is McCoy
Quinto- was great as Spock, though I had to get use to not seeing him as Sylar
Pine- was great the entire movie, but towards the end of the film, he just became Captain Kirk to me.
I've been a fan of Bruce Greenword since Thirteen Days, he was great.
Jennifer Morrison-wish she was in it more, fan of her on House.
They were all great. Oh and I did see a little bit Of Pegg, instead of Scotty, but still he was great.
Uhura-was great as well, can't to see Zoe Saldana in James Cameron Avatar.