All of them were good.

A guy who went under contract for a condo and then broke in and stayed for a weekend and then a month later changed his mind and defaulted.

All of them are 'good'!

Everyone did something good to me - they bought or sold the home through me.

Looks like William nailed this one!

I had a client lie about his loan, lied to the loan officer about income and then broke into the home he wanted to buy and moved in a week before closing.

A divorce sale, he hires me, she hates me becuase he hired me. Court issues order to koeep my as listing agent. Fast forward get a buyer, accepted offer, heading to closing asking for seperate rooms for ex husband and wife may not have been enough seperation as the ex wife screams at the ex husband myself and the buyer. She is removed from building. Later that day husband gets court order for her to sign and it closed, worst closing ever.

Tom, closing his store and trying to lease out the space. Would only overprice it because he knew more than I. Wouldn't do rudimentary prep work either, because he knew better than I.  Over a few months he got the message and did the prep work. Got him a full price offer for 10 years with escalator clauses. After verbal agreement he tried to change the terms at the literal last second before signing. Lessee said no. Tom wanted to retain the deposit anyway.  He was truly the last client that caused me to lose sleep.  

A seller referred to me by a member of my family of origin.

I could not fire them.

Rather than communicate with me, I received direction and suggestion via the family grapevine. 

This made the 'client' the apparent hub of gossip, a position coveted greatly and asserted oppressively, and with the greatest intent of mischief. 

Personal calamity distracted the subject for a duration of time sufficient for our agreement to fade away.

Everyone, friend, family and foe was damaged due to this misguided choice. That is the nature of gossip.