From Andre The Giant to Shawn Michaels and from Triple H to Edge without forgetting Randy Orton, the heel characters have always been essential to WWE success.
Traditionally, with the likes of Andre and The Iron Sheik, the heel figures generated as much heat as today's bad guys. But they didn't have a huge fans base as today's Chris Jericho or CM Punk.
That being said, let me present you the two main requirements to have a solid heel run.
1. Generating actual heat
The fans don't want cheap heat such as Sheamus attacks on HHH or Cena. Those aggressions will only generate short term heat; and the wrestler using such tactics will have to work hard to convince the crowds about his villain gimmick.
Being just brutal without any efficient promos on the microphone will lead nowhere.
There must also have a story behind a wrestler's heel behavior and/or a perfectly played gimmick.
Andre The Giant could be heel simply by squashing and brutalizing the face characters; but he went with more than just being a monster size gimmick: the creative team went with a great betrayal story-line between him and Hulk Hogan.
With the assistance of Bobby Heenan as his manager, Andre then capitalized with that famous Wrestlemania III moment and continued with his amazing heel character for years.
Take Big Show or The Great Khali for example : they hardly generate legitimate and permanent heat.
From time to time, they hit some top faces with their giant size bodies to produce a short-lived feud; here, think about Big Show and Cena in the spotlight or Khali with The Undertaker to get the point. Now, try to remember their feuds and you will search far in your memory.
There's nothing like outstanding mic skills or amazing presence in a ring. It's all in the attitude.
Rick Rude comes to mind when we talk about cocky attitude; he was an innovator with his personal insults to the fans and his body showing. His mic work combined with nasty use of his body made of him one of the best heel in WWE history.
The Million Dollar Man Ted DiBiase was an other one of a kind heel. His promos were priceless (pun intended) and, seriously, he and Virgil generated heat like no other. JBL and I.R.S. have been the best Ted DiBiase's students so far.
Nowadays (and fortunately) the WWE still have amazing heels who can generate actual heat.
Edge is the first I think about when I think about the classic modern bad guy. His nickname, The Ultimate Opportunist , says it all: always jump on the opportunity to win championships or any given matches and never hesitate to use any means necessary to do it.
Chris Jericho is the perfect prototype of today's heel mic worker; personal insults to the crowds is his favorite heat generator and he will always reminds the audiences about how great he is. In addition, to generate even more heat, he wins Title matches on occasions.
Randy Orton is another kind of heel. The Viper is a well deserved nickname and describes perfectly his gimmick. There's no one nastier and sneakier than The Legend Killer who built his reputation on the brutal aggressions against iconic wrestlers.
His charisma combined with his predator's behavior is what is making Orton's legacy (pun intended).
CM Punk is currently the greatest rising star with his heel straight edge gimmick. He got is so naturally, it's almost freaking. With the stable he is building, he might be one of the best heel of all times if he is not stopped by the WWE creative team.
2. Having a huge fans base :
Today's most successful heels will always have a huge fans base because many wrestling fans really appreciate the efforts behind delivering a solid bad guy gimmick. Edge, Chris Jericho, Randy Orton and CM Punk are the top heels in recent history who established new standards.
What they have in common is the hardcore fans base, that is particularly active on the web. Back in the Old School days, the heel characters were often abandoned by their fans who liked them when they were faces. It was harder in those days to be a heel because the fans often taken wrestling too seriously and actually hated the villains.
I would say the transition has been made with wrestlers such as Ric Flair, who joined the WWE in 1991 with an already legendary background, or Shawn Michaels, who still had fans despite he turned heel; he generated tons of heat with what he did to Marty Jannetty, but his Heartbreak Kid gimmick seemed to please the ladies so he had a female fans base.
Then, after HBK and before the modern days top heels, there were Bret Hart, Mankind, Kane, The Undertaker and Triple H who have set the stage for the future heels.
As you can see, the wrestlers such as Sheamus, Big Show, and Vladimir Kozlov lack the ''it'' factor to become heels who will let a memorable mark in the WWE history books.
To conclude on the importance of the top heels in WWE, it would not be exaggerated to say that without heels there would be no show.
Most of the times, they carry the faces match after match and they usually lead the promos leading to pay-per-view matches.
Without the greatness of Edge or Orton, Cena would not be the top face we know today. Same with Batista, who got it very good with his heel turn.
As always, personal feuds will attract even more heat and fans. Batista vs. Mysterio and Orton vs. Cena or HHH are the best examples in recent history, just like the Rockers and Mega Powers breakups for Old School history.
As an old man said, there's no heaven without hell and, translated in wrestling language, there are no good guys without bad guys.