Which medical specialties do physicians have a more comfortable/fun lifestyle? i'm leaning towards radiology...

Medical School First: First, get into Med School, then, do the work, go through your different clinical rotations, take electives in those areas you think you are interested in. Most people I knew were not a good match for Radiology. If the fit is poor then the lifestyle cannot be good. You need to be able to be a consultant for other physicians. Good Luck.

Each his own: Expose yourself to a variety of specialties , the work of being a physician should be interesting, satisfying and enjoyable. You can create a suitable lifestyle in any profession.