We're going to look through the books and movies to find the most terrifying, soul-sucking Dementors of them all. We're also going to scoff at the lamest Dementors to ever float about making every day feel a bit like Monday. Want an excuse to eat chocolate? Then here's the list for you!
On one hand, Dementors are Harry Potter's Achilles heel. They cut through his bravery right to his worst memories, like a free-floating Horcrux coming to make out! Fortunately, they're as dangerous as they are easily defeated. Like many of us, they're vulnerable to chocolate and nostalgia. So, what separates the top-tier terrors from the lazy, lame moaners? Read on! You'll also see how you can repeatedly use 'sucking' as both a negative and positive!
Worst: Hodor-mentor
These Dementors are just being lazy! Considering they can clearly reach through the bars of the elevator, we know the ministry hasn't put a defensive charm there. We know they can open doors because they did so on the Hogwarts Express the first time we saw them. The Dementor equivalent of 'hold me back, Dementor-Steve! I'd totally suck this guy's soul if you weren't holding me back! Oh, I lament your considerable 'back-holding' skills that preclude me sucking this guys soul!'. This is just poor work all round.
Best: Bad Weather Fans
You could take marks off for leaving their posts, but you've gotta give it to the Dementor who knocked 'The Boy Who Lived' off of his broom with sheer halitosis. As Harry and Gryffindor were battling Quidditch "powerhouse" Hufflepuff, these Dementors got a bit too frisky for the faculty's liking. We actually see one right up in Harry's proverbial 'grill' giving his soul a suggestive suckle and that takes him out of the game completely. Clearly meant for bigger things than guarding the local school.
Worst: Duhhh-mentor
You know when you get an assignment with clear instructions, but your partner wants to take the easy way out and ends up ignoring those instructions entirely? That's this Dementor. Tasked with getting Harry Potter, this one decides to detour into Dudleyville. While his partner stays on the job, he sees 'Big D' as an easier, Patronus-less target to gorge on mid-mission. Back to Dementor Detention for you!
Best: Tunnel Of Love
Of course, while the previous Dementor was slacking off by picking easy but non-essential prey, this guy was on the job! This Dementor had Harry right where he wanted him. In pro-wrestling parlance, he 'goozled' him by the neck and was seconds away from tasting 'Boy Who Lived' soul. If Duhh-mentor had have been on the lookout, these two probably would've gotten the cookies. Points for the near-miss, though.
Worst: Jury Duty
You've got to be a pretty underwhelming Dementor to get assigned to 'float around the ministry ceiling' duty. These Dementors aren't just doing the laziest of work, they're put in a position to be getting the Dementor equivalent of a sunburn. With Delores Umbridge's Patronus sat right there—shudder to think of her 'happy thought' that conjured it—it'd be like floating above Chernobyl. The lowliest government job available.
Best: Death Smoocher
Now here's a Dementor committed to doing its job and doing it right. This one clearly remembers that Barty Crouch Jr was supposed to be buried in Azkaban, not alive cosplaying as Bill Weasley's dad. With the shot to suck out his soul, this dementor wastes no time and gets the tongue in. In the grand scheme of things, he probably hurt Voldemort's overall odds, and thus the Dementors chances at becoming the national bird, but, at the time, it was the play of the week.
Worst: Don't Bogart My Chocolate, Man
The only thing worse than a lame Dementor is something pretending to be one. The Bogart in Professor Moody's office is little more than a Dementor-shaped punching bag for Harry to repeatedly beat down.
Curiously still able to give off the Dementor's depressing effects, it is nonetheless also guilty of being a spider on rollerskates in its spare time or being easily defeated in the Tri-Wizard maze. Quite frankly, it was far more terrifying when it turned into a creepy pop-up clown or Fashionista Snape.
Best: Training Day-mentor
The first dementor we ever meet and clearly a potent one at that. This guy manages to frost up an entire train filled with kids fresh off of candy from the cart.
Not only that, but he also manages to find the one kid with the tastiest and most deliciously terrible past and almost ends the series at Book 3. Harry Potter and the Half-A-Train-Ride-Before-He's-A-Gormless-Soulless-Shell wouldn't have sold half as many copies. Plus, it would've been about as long as a pamphlet. If not for Professor Lupin, this one could've topped the list.
Worst: Dercrabbe Malfoylor
"Dementors" mostly in the sense that this plan was demented. When Draco, Crabbe, Goyle, and Marcus Flint waddled onto the Quidditch pitch dressed as Dementors, it showed the reason Slytherin's aren't known as intellectual powerhouses. Lacking the depressing effect, weather manipulation, and generally everything that goes with Dementors, they thought some cheap cloaks would suffice in spooking Harry out of the game. When you're such a sad Dementor that you lose 50 points for Slytherin just for showing up, you suck. In the ineffectual lame way.
Best: Lakeside Lover
The Dementors that came as close as Voldemort to ending 'The Boy Who Lived'. With Sirius unconscious and Harry unable to execute his Patronus Charm, this squad of soul suckers almost did the deed. It might've even still allowed for the prophecy to be true since a soulless Harry would still be 'alive' for Voldemort to kill later. Convenient.
When you are about to succeed only for time-traveling duplicates to foil your plan, you can still call it a moral victory, assuming your morals are 'suck souls, make bank.' We should assume all dementors have that tattooed somewhere. Probably a tramp stamp. Hence the cloaks.