Arson, Murder, and Admiration

When two villainous (or at least, Token Evil) characters fight, the less evil one will rail about how Even Evil Has Standards, they've crossed the Moral Event Horizon and what they've done is unforgivable... and it was a nice touch to put lasers on the carnivorous hamsters' heads.

Mostly a comedy trope, this shows up as an inversion of Arson, Murder, and Jaywalking with one villain complimenting another on how Stylish their Death Trap, Evil Plan, Villainous Monologue, Evil Laugh, Villain Song, or they themselves are.

It won't stop them from fighting it out, but credit where credit is due.

If it's a Villain Team-Up, the Card Carrying Villains will often compliment their allies/rivals for their evilness. Compare Arson, Murder, and Lifesaving. Compare In Love with Your Carnage when a villain falls in love with a hero due to the hero's violence. Contrast Insult Backfire. If a hero or other non-villain is on the receiving end, this becomes Your Approval Fills Me with Shame or just Baddie Flattery.

Films
"Morticia: You have enslaved him. You have placed Fester under some strange sexual spell. I respect that. But please, may we see him? [later] Morticia: You have gone too far. You have married Fester, you have destroyed his spirit, you have taken him from us. All that I could forgive. But Debbie... Debbie: What? Morticia: ... pastels?"
 * Morticia in The Addams Family films lives this trope.
 * In the first movie, Morticia compliments the man stretching her on the rack (who is sweating over the evil deed) as "having done this before". She also believes that she and the female antagonist could have been good friends were it not for the current unpleasantness.
 * The second film has the following exchanges between Morticia and Debbie:

"Drebin (undercover as a gangster, to the Big Bad's mother): Mrs. Dillon, your son is a ruthless, sadistic, cold-blooded animal. You must be very proud of him. Muriel Dillon: I am."
 * The Naked Gun 33 1/3: The Final Insult:

"Jabba: "Hohoho! This bounty hunter is my kind of scum! Fearless and inventive!""
 * Jabba and Boussh in Return of the Jedi:

Literature

 * Dexter greatly admires the artistic merits of the Ice Truck Killer's scenes. In the second book, he also admits to respecting the spoke of turning people into "yodeling potatoes".
 * In the Discworld book Mort a dying Evil Vizier takes this trope up to eleven: he compliments the emperor for killing him.

Live-Action TV
""You're more ruthless than me, crueler than me. Maybe you are better than me. I'm proud of you son.""
 * Dexter again (this time only the TV show) admits, at least at first, that he admires Trinity for his success in maintaining the life he's led. Partially subverted in that Dexter still has every intention of KILLING him, but not before he can learn how to do the same with his own life.
 * Judging from how fondly he refers to a lot of his victims ("playmates"), Dexter has a lot of this going on. It's just that he kills killers and they are, well, killers.
 * In Leverage, after Nate cons his dad into a situation where the Irish mob puts a contract out on him:

"Bishop: You fiend! Never have I encountered such corrupt and foul-minded perversity! Have you ever considered a career in the Church?"
 * Blackadder II features one after Blackadder blackmails the Baby-Eating Bishop of Bath and Wells who "drowns babies at their christening and eats them in the vestry afterwards" by arranging some very compromising paintings.

Professional Wrestling

 * Used occasionally, such as when, after being betrayed by his tag-team partner Christian in a Battle Royal for the Intercontinental belt, Chris Jericho called him out...to congratulate him, and tell him he would have done the exact same thing if he'd thought of it. Then they hug. Awww.

Web Comics

 * 8-Bit Theater has Evil Princess Sara be "this close" to being proud of Garland after he got a villain upgrade with dark colored Speech Bubble. He's still a nice, Harmless, Affably Evil Ineffectual Sympathetic Villain though, which explains the almost.
 * Inverted in Looking for Group, where Richard is criticized on not being evil enough.
 * Well, it was by a Kangaroo Court set up by The Legions of Hell...
 * Jenny in Order of the Stick, who met with and got a heavy crush on Belkar.
 * Tarquin, to Roy after the latter caused major structural damage to the gladiator games arena. Roy is somewhat bewildered.
 * In Tales From the Pit, Mark Rosewater receives hate-mail from an angry Magic player who accuses him of having "sytematically destroyed everything that was awesome about Magic" immediately before asking how to get a job in R&D.

Video Games

 * In Disgaea: Hour of Darkness, Etna uses Villain Protagonist Laharl as bait to get what she wants from Big Bad Wannabe Maderas, without either of them knowing. After Laharl finds out what Etna's intentions were, does he get angry at her for using him? ...no, he compliments her on how devious she is and promotes her to his right hand demon.
 * Due to their lack of any actual morality, some Asurans in Guild Wars come off as somewhat evil. In one case the actions of the Asuran Tekks has instigated a war between two aboriginal frog-tribes. Her rival, Giriff, comments he would be impressed if he thought she'd done it on purpose.

Web Original

 * Inverted on Red vs. Blue: while Sarge is glad that O'Malley is killing all the Blues, he can't stand the thought that he now has a higher body count.

Western Animation
"Shredder: Then you shall have the robot. I vow it! Krang: Cross your heart and hope to die? Shredder: What heart? Krang: Shredder, you're my kind of guy!"
 * In the old Teenage Mutant Ninja Turtles cartoon, Shredder and Krang would occasionally compliment each other's evilness (when they weren't getting on each other's nerves). Other villains also got some praise for their evil plans from time to time.

"Lucius: Someone is causing misery? At this hour? How productive!"
 * In A Sitch In Time, Evil Overlord-wannabe turned Dragon Dr. Drakken complains that Shego has very poor villain form by refusing to gloat over her victory.
 * On Jimmy Two-Shoes, after Lucius is woken up in the middle of the night:

"Megabyte: What you did was slimy, contemptible and downright distasteful. I loved it!"
 * During the "Identity Crisis" episode of ReBoot, after Sirus had stolen a file containing the PIDs for a sector under Megabyte's control:

Real Life

 * After Pearl Harbor, Adolf Hitler was so pleased that he declared Japanese to be "honorary Aryans". He also declared war on the United States in support. The second was not his brightest idea.
 * Although the US didn't have an impressive army back then. Actually, conscription was the only way to get an army of any significance together. Well, that's one thing that has changed!
 * America's Army size was of limited advantage. Panzers cannot swim. And that calculation would have been based on present size when the future expansion was most important. Furthermore America's navy (which could of course cross the ocean) was top-of-the-line and the German navy, except for commerce raiders, was kind of not.