Note that the below list is a very rough scale; any given character may fall higher or lower on this list depending on context, regardless of what tropes describe him. Many character types are very broad, so the positions below should represent an approximate average; some individual characters are subversions who turn out to be something significantly different from the stereotype of their type of villain.
A truly Despicable villain is someone we hate and revile, while a truly Evil villain is dangerous and to be feared- we care less about what happens to him and are satisfied that something does, if only to end his reign of terror.
This scale goes from the most Sympathetic to the Least Sympathetic
•Heroic Antagonists◦Sympathetic Inspector Antagonist
◦Characters that believe the protagonists to be criminals and seeks to capture them
◦The Rival
•Anti Villian◦Those Forced Into being Evil
◦Misunderstood Monster
◦Obliviously Evil
◦Harmless Villain/Ineffectual and Sympathetic Villain
◦Worthy Opponent
◦ Minion with an F in Evil
◦ Noble Villians
◦ Villains who just follow orders
◦Well-Intentioned Extremist
•Ordinary Villian◦The Villainous Clown
◦Smug Snake is often here or lower
◦Obviously Evil Villians
◦Bigger Bad is this or lower, he might even be more sympathetic, if Mr. Big Bad is a Complete Monster
•Characters likely to cross the Line◦Faux Affably Evil when they are not Complete Monsters.
◦Monster Clowns typically goes about here when not overlapping with Complete Monster.
◦Social Darwinists usually lands here or lower.
◦Psycho for Hire
•Any antagonist who has already crossed the Line many times◦Complete Monster - By definition, the least sympathetic character possible.