If you like any of them after shadowing the doc then go for it. If not think about how much you'd be willing to pay to do something you "love" with the understanding that after doing it for a couple years it will still be just a job.
I love what I do (oncologist) but most days it wouldn't make a difference in my happiness if I had taken that investment banking job 15 years ago and I'd definitely have a lot more money if I'd gone that route.