Sofiane instantly jumps out as this year's "Candidate Lord Sugar will see himself in" and thus I think he'll get quite far.
I also like Samuel, Oliver and Karthik, though the latter will probably just end up as "comedy relief" similar to Jason or Felipe and get fired around about the halfway point.
Going off nothing but the first episode, the only candidate to actually have some sense and show *some* degree of skill (outside of Sofiane), was Trishna.
So I think *going solely off the first episode* she could be a dark horse.
Of course, it's far too early days, but she gets my vote.
EDIT: People legitimately think Jessica will win?

Lord Sugar strikes me as the type of guy who isn't going to stand being in a room with her for more than an hour, how on earth do people believe he'll be happy to go into business with her