If you're a writer and have yet to watch Breaking Bad, do yourself a favor and check it out. You want to know how to write the perfect antagonist/villain? Sink your teeth into this excellent t.v. series. You can thank me later--after you've managed to climb out of the butt hole molded into your couch.
I was trying to explain to my wife why I love Breaking Bad the other day. (I had just turned off the t.v. after a bleary-eyed ten episode marathon.) This is what I came up with: I am able to sympathize (and the ability to sympathize with is the all-important key to a character's success) with Walter because of two things: 1. He is bad at being bad. Walter White tries so hard to be the baddest dude around, but no matter what he does, he is always one-uped by the real bad guys. (One-baded doesn't quite make sense.) 2. He tries so hard to be bad yet still cares for his family, and so has some remaining ounces of humanity. I despise everything else about Walter's character. I won't give anything away, but he gets bad. Evil. Totally insane. My wife isn't aware of this, but I was in tears (from shock, not empathy) at the end of a certain episode. It is painful to see a man fall so far. If it weren't for Walter's being such a terrible bad guy, I'd tell everyone to avoid the show. The writers are brilliant, however. They create perfect believability in Walter's journey into darkness. It's pathetic, it's irrational, it's terrifying. He is a character viewers and writers will not forget.
Seasons 1-4 are available on Netflix, and the fifth and final season is currently airing on AMC. Another thing the people behind Breaking Bad are doing right is ending it. All great stories have to end, and they are doing it at the perfect time--when the show is at its peak.