It's so hard to answer your question because it is a matter of opinion and temperament. Not to mention experiences can greatly vary. My medical school made all of us experience both before graduation for at least three months. I highly recommend you try both too.
Agree with getting your feet wet with both if possible. I started off in the more basic science type research, now I'm doing an epidemiology grad program and have had some involvement in clinical research. I like each quite a bit, though for very different reasons.