The trick to writing a memorable bad guy is to get your reader to root for him on some level.
Example: In A HEART DECEIVED, bad guy Nigel Thorne is a real rotten fella. Think Grinch. Garlic in his soul. Heart's a dead tomato. Yada, yada. But throughout the story, poor ol' Nigel's got an even worse scoundrel after him, which drives him to antagonize Ethan the hero. Savvy?
There are many ingredients that go into crafting a character readers love to hate, but here are the top 3...
Make your bully as icky as you want but give him a teddy bear...or some other quirk that shows he's got a chink in his bad boy armor. This creates sympathy in the heart of a reader.
A villain is more interesting if a few others consider him good or trustworthy. Granted, those others might be deluded or bad guys themselves, but hey, loyalty of any kind is an admirable trait. Your antagonist MUST have something in him that others respect, something that a reader can respect, or he's not going to be believable.
A great nemesis must stop at nothing, for any reason. Ever. One of the most frightening things about a really evil dude is when they just won't quit. A hero wouldn't look quite as heroic if he was up against a bad guy who took his ball and ran home, right?
Weave these traits into your next thug to create a memorable villain.