I've liked Jim from the start.

He came across very well on this week's episode. I like his personality, he seems very happy in his own skin, confident but not delusional, and with a good sense of humour. He's also got an abundance of backbone and he's astonishingly articulate and quick witted for an apprentice candidate too
The Final Five programme tonight also showed him in a very good light, particularly when they interviewed his wife. He seems to be a decent, good-natured guy, with a refreshing degree of self-awareness.
If I had to put money on someone at this point, it would be him. I'd be astonished if he doesn't at least make runner-up (to Helen, I can't see any other candidate pipping him to it now).