However, when she didn't want to play ball, Lear blows up, casts her out, and gets rid of one of the few people who will stay true to him throughout the entire play (Kent). Now Lear isn't necessarily a villain except unto himself, and by that I mean he splits up the possible support group he could have had when his madness takes over. That moment in act 1 scene 1, was the catalyst for the entire play, and if he had the common sense not to cast out his only loyal daughter, then he might not have had those horrible problems he did in the play. By doing those things, he left a small opening for Edmund to start working his magic, but I"ll get to him later.
Posthumus is the luckiest out of all these villains. Again, he wasn't really the main villain of the play, it looked as if the queen was making all the moves in the beginning, but if he hadn't have made a bet with Jachimo, Imogen never would have faced those odd situations. .
"I will wage against your gold, gold to it. My ring I hold dear as my finger, "tis part of it" (I.4.132&133).
He wants Imogen dead after believing Jachimo's trickery, then becomes a bit of a woman-hater. Throughout most of the play, he's filled with hate and self-pity (somewhat) and at the end when all is revealed, Imogen actually takes him back. All that leaves him with is the fact that he couldn't trust his wife. That's like a slap on the hand. Oh boy.
Although Othello isn't a villain, he had villainistic tendencies. After Iago planted enough seeds in him, Othello would blow up at his wife in public. He slapped Ophelia and called her outside her name. As strong and intelligent a person he was, if he had the common sense to just confront Cassio and Ophelia, then this whole mess would have been straightened out. By listening to Iago "tap-dance" around his head, Othello helped cause a lot of grief around the entire state, and not to mention the death of his wife by his own hands.