While I can generally get along with anyone, I do have a loose rule-of-thumb when it comes to my camping mates; that being  I won't trip with the "3 C's": Cops, Clergy or Californians.

Cops - ALWAYS need to be in charge.  I have yet to meet an exception.

Clergy - Too many "rules" and cannot typically handle the unexpected.  There are some exceptions but most just like to hear themselves talk.

Californians - just goofy all around and typically need to change clothes 4-5 times a day.

However, the person I cannot stand to trip with is usually me.  I have a tendency to sleep late, burn dinner, lose fish, be indecisive, get lost occasionally and often forget items in the car or at home.  Plus, I'm a real jerk.