Among the many reasons why Marvel rules the roost when it comes to the comic book movie game, it's the studio's willingness to part ways with its most beloved figures. From major deaths in the "Avengers" movies to minor characters kicking the bucket in smaller but no less tragic moments, Marvel knows how to break your heart by killing off its darlings.

With that said, here are the saddest deaths the Marvel Cinematic Universe has offered up so far — and one crowning death that never actually happened… not yet, at least.

WARNING: Spoilers for all of the Marvel movies AND television shows ahead!

TIE: The Original Bruce Banner and James "Rhodey" Rhodes

Not that either character died, of course. But Hulk and War Machine's original actors, Ed Norton and Terrence Howard respectively, took a hike after their first and only rounds in the Marvel Cinematic Universe. I'm very happy with our Mark Ruffalo and Don Cheadles of the world, thank you very much, but still, I'd be lying if I said I didn't think about the alternate universe where Norton and Howard just high-fived over their record-breaking "Avengers" success.

TIE: The Loki and Nick Fury Fake-Outs

Lame! I mean, I love you guys, but lame. Totally lame. Thor's brother and the S.H.I.E.L.D. director totally stole some tears in their supposed "deaths scenes" during "Thor: The Dark World" and "Captain America: The Winter Soldier," respectively, but psyche! It was a prank! We got Loki'd! Terrific and heartbreaking moments, both of them, but total lies. Points for initial emotional impact and creativity, though.

The Other

His sudden death at the hands of Ronan the Accuser was actually pretty hilarious, but also a very sad and abrupt ending for Alexis Denisof's time with Marvel.

Agent Sitwell

This one sucks, because Sitwell seemed so legit — until we found out that he was working with HYDRA. You're left feeling two parts pumped and one part bummed when he gets thrown into a truck during "Winter Soldier." At least it's one less HYDRA to deal with, but still, he was our friend… at least we thought so.

Maya Hansen

Like Sitwell, Tony's old scientist pal appeared to be on the level, but surprise! She's working with Aldrich Killian, and that sucks. You feel bad for her when she goes, but you can't help but feel a little bit of "toldja" caught in your throat.

Obadiah Stane

The Dude does not abide! He certainly earned his fate, but the "Iron Man" villain, and Marvel's first-ever bad guy, was more of a greedy prick with a high-powered suit of armor than anything else. And like Sitwell, he was a buddy once upon a time. Sad to see the mighty fall so far.

James Wesley

Wilson Fisk's right hand man and best friend was not a good person. Let's get that out of the way. Fisk, too, is a bad dude. But among the many reasons "Daredevil" rocks is the show's ability to get you invested in Fisk's side of the battlefield. When he loses his best pal, you can't help but feel you've lost someone, too.

Anton Vanko

The death of Whiplash's daddy pushes Mickey Rourke's Russian rogue into action against Tony Stark, and you can't blame him for seeking out a little bit of vengeance, given Tony's father being such an arrogant jerk in his past. It's less sad when Ivan dies, because, you know, the whole mechanically-enhanced murderer thing. But when his father passes away at the top of "Iron Man 2," you're invested in this strange little bird's journey.

Howard Stark

We've yet to see how exactly Tony's dad died, but his absence alone is enough. There's no question that the Avengers squad's signature billionaire playboy philanthropist carries some daddy issues inside his suit of armor, and you can understand why, given the time we've spent with Howard in "Agent Carter" and the like.

Frigga

Thor and Loki's mommy dearest pays the ultimate price in "Thor: The Dark World," adding an unexpected layer of tragedy to the siblings turned rivals' relationship. While Marvel never quite figured out how to make Frigga work on her own two feet, her demise galvanizes everything that happens next in the second "Thor."

Garthan Saal

He might've considered the Guardians of the Galaxy a bunch of a-holes, but he was OUR a-hole.

Professor Yinsen

Without Yinsen, Tony Stark never leaves the cave. He never becomes Iron Man. We owe a lot to this man — 11 movies and counting, to be precise.

Abraham Erskine

Like Yinsen with Iron Man, there is no Captain America without Doctor Erskine and his super soldier serum. Stanley Tucci plays the character with all the warmth we subsequently see out of Steve Rogers, making his sudden death incredibly tough to swallow.

Agent Triplett

Devastated does not begin to describe how I felt watching the Howling Commandoes descendant crumble into dust as Daisy "Skye" Johnson embraced her super heroic destiny, and I know I'm not alone. It was the most brutal moment of "Agents of S.H.I.E.L.D." yet, and it's not close.

Roger Dooley

"Atta girl." With those two final words, the SSR's crotchety chief made "Agent Carter" fans realize just how much they would miss his surly attitude, even after all the times he ignored Peggy's wisdom.

Ben Urich

This should not have happened. Straight up. He's a big character from the comics! He had so much left to do! You can't just kill Ben Urich! And yet, Wilson Fisk does not play by your rules. Fisk choking the life out of the most noble man on "Daredevil" was a defining mission statement for the series, proving that Marvel's first Netflix outing marches to the beat of its own deadly drummer.

Quicksilver

Like Urich's death, this should not have happened. Double straight up. He's not just a big character from the comics — he's a superhero! With decades of history! You can't just kill Quicksilver! And yet, Joss Whedon does not play by your rules. In killing Pietro, Marvel proved exactly why they're the king of the ring where superhero movies and blockbusters are concerned. You can't walk into their movies and expect a consequence-free ride. Yes, there's fluff, but there's also stuff — painful, lethal stuff, evidenced by one of the franchise's very own name brand heroes speeding off toward the great beyond.

Ultron

Yeah, I'm going to say it. Ultron's death was the saddest death in all of "Age of Ultron." Credit James Spader's phenomenal portrayal of a deeply wounded droid. Credit Whedon's writing, his directing, the way that Vision so artfully incinerates his artificial contemporary in the cold light of day. It's sad, despite everything Ultron put our heroes and Sokovia through. It's beautiful, too; Ultron's death stands out as one of the most haunting and breathtaking images in the entire Marvel Studios catalogue, let alone "Age of Ultron."

Agent Coulson

He's not really dead anymore, but he did really die at the time, and it was really horrible when it happened. Luckily he's still up and at 'em on "Agents of S.H.I.E.L.D.," but as far as the movies go, Phil Coulson's dead, and I'm still pretty bummed.

Groot

Sure, it's kind of a fake-out ala Loki + Fury. Groot returns by the end of "Guardians of the Galaxy." But your argument is invalid because WE ARE GROOT and I still have snotty tears running down my face.

Captain America (Hear Me Out!)

The world thought Captain America died in the 1940s. The world was wrong, but the emotional devastation caused by his "death" was very real. Look no further than Peggy Carter. Even Cap himself is haunted by the decades he missed, the life he lost, the dance that never was. In a very real way, Steve Rogers' entire story is all about death and rebirth.

If that's not good enough for you, then just wait a year. "Captain America: Civil War" comes out in May 2016, and people who have read the comics its based on are already preparing themselves for the worst. You might want to do the same.