Well, my suggestion is to just try some and find what you like. Be aware that miso soup in restuarants starts with "dashi" which is japanese sea stock . So, if you make it at home it probably won't taste the same and that is why. You can make your own dashi pretty easily if you can track down the konbu & bonito- easy to find here, I'm not sure that's the case everywhere.
Anyway- Bonito is fish so I always make my miso without it at home. I like the fuller flavored misos. Typically, the lighter the miso the lighter the flavor. You can also use it for a lot of other things like marinades and salad dressings.