Whilst no one posting here is in a position to tell you which to hire, I'd like to offer a little counterpoint to the proceedings...
One of our most recent new starters is the absolute image of professional experience.
In at 9, out at 5, one hour for lunch. No lates, no weekends.
Which probibly sounds terrible to most of the people who have responded so far.
However, not only is his code better (clean, concise, patterned, understandable, maintainable, test, on time!) than most any other team member, he is also an excelent sounding board for the passionate devs when they think they are about to solve all of our woes is a single deployment, a fountain of knowledge, and a voice sanity saving us from ourselves.
He knows how to push back against pushy management. He can spot scope creep a mile down the road. He writes more unit tests than anyone else. He doesn't b*tch and moan when he gets lumped with a boring task, and he'll probably still be here in 5 years time.
(To add to my first answer)
How do you know the passionate bloke is passionate other than the fact he told you?
He might be doing his best keen face because he so desperately needs the job, people will say most anything to get a job at the moment
He might think he's passionate about coding, but will the sheen start to tarnish when he realises 99% of us don't write sexy code.
Experience is quantifiable and provable.
Experience know that day-to-day, most of us work on non-sexy systems and dirty legacy code. And Experience shows that they can still drag themselves out of bed in the morning to deal with that.
I would like to reiterate I am not telling anyone who to hire. I do not think experience is better than passion or vice versa. I am not on a massive downer about people who are passionate about coding, but I find it a little worry to see the lack of balance being presented here. All of the other top voted answers here make very good valid arguments (Matthew Kubicina, User 9094, Otávio Décio, Bernard Dy) and I have voted them as such even if I have reservations about some of their opinions.