Perhaps the most difficult people not to judge are ourselves; after all, we live with ourselves all the time and can easily see all of the silly, stupid, dramatic, and insane things that transpire in the course of a day. Length of time and proximity/intimacy are a good measure of whom we are more likely to judge, even while exonerating.
This leads us to the next two persons/groups we are most likely to judge--God and family.
Yes, God. I don't know about you, but I know I have spent a lot of time judging God. I didn't think of it in those terms, and I'm not certain I've come to understand it in the way I should. However, I can't imagine that I'm all that unusual--judging God and His power and will seem to be a daily part of our lives.
This question is most prominent when we face the foundational question of the problem of pain. How we choose to address it both in the abstract and in its more personal application is a good indicator of where we stand in judging God. Many an atheist has looked at the problem of pain and has concluded that it is not possible to have a God of boundless compassion and a God who allows terrible things to happen--therefore, there is no God--perhaps the ultimate judgment on God.
C.S. Lewis produced a book of essays titled God in the Dock. As the title suggests, he makes the case for this kind of treatment of God at far greater length and with a great deal more eloquence than I can summon. Suffice to say that a great many of us, even those of us who like to think of ourselves as profound and witnessing Christians, have the hubris to believe that we can and should stand in judgment on God.
Needless to say, the presumption is so overblown that it becomes almost a work of art--the most massive monument to human self-esteem that could be conceived. And in all likelihood it is safe to guess that the self-esteem that it reflects is, perhaps, a little out of proportion to the cause.
One of the most serious problems with judgment is that it assumes a grounds, a basis for making any judgment. That can be knowledge or authority or anything that gives one sufficient merit and status to make broad, general, evaluations.
Comparing human beings and God on all merit leaves one to wonder where one could find sufficient grounds for permitting judgment. And yet, grounds or no, too often we presume to do so--and much to our own detriment. The only thing that judging God is likely to do is alienate us from Him. Not, mind you Him from us, because our follies and misconceived notions are of the moment and (in all likelihood) as amusing to him as are the dicta that emerge from the mouths of toddlers--filled with a kind of uncanny and situational wisdom, but hardly a light for all time. And God, we must recall, uniate in substance, is boundless compassion and love--He knows what it is to be human and so bears with the pettiness that can be human judgment.