to find the most comfortable handlebar option for you, you'll need to try a good number of them and give each a few thousand miles. not cheap or practicable for most, so most never find the most comfortable handlebar.

i've used drops, flat, and bullhorns, giving each a good chance at satisfying me. i've settled on flat bars, but don't necessarily recommend them one way or another. and i suppose it could just be that i ride singlespeed and do a lot of climbing. who knows? good luck.