To add to the quote below, I find that when I interact with people in this mode -- love them without asking for something else in return -- that I am much happier and much more effective in my own life. Being annoyed at every little foible of others brings me no joy.
Nancy White propogates a thought, so I will do the same:
Our job is to love others without stopping to inquire whether or not they are worthy. That is not our business and, in fact, it is nobody's business. What we are asked to do is to love, and this love itself will render both ourselves and our neighbors worthy if anything can.
-- Thomas Merton