Genres fall in and out of favor in Hollywood. Westerns, gangster pictures, sword-and-sandal historical epics - each one had its day in the sun before sliding into the niche. In the 21st century, it's the superhero movie that dominates multiplexes. Superheroes have made greater cultural impact on film than they ever did in their native comic books.

RELATED: Every Movie Sam Raimi Has Directed (That Isn't Spider-Man Or Evil Dead)

The superhero train shows few signs of slowing down, even as its prominence has gone from an abundance to a glut. Some years saw far more superhero movie releases than others.

10 2004 Saw Five Superhero Movies Released

2004 Superhero Movies

The early 2000s are the root of the superhero boom, but were a mere taste of what was to come. Three Marvel adaptations, all produced by different studios, were released. Sam Raimi's Spider-Man 2 (Sony), David Goyer's Blade Trinity (New Line Cinema), and Jonathan Hensleigh's The Punisher (Lionsgate). WB also delivered a loose DC adaptation with Catwoman.

Of these, Spider-Man 2 was the clear victor - critically and commercially. However, 2004 was also the release year of Brad Bird's The Incredibles, which proved you don't need comic book source material for excellence.

9 2005 Escalated From 2004, With Six Superhero Movies

2005 Movies

The following year didn't see things slow down. On the DC side, Batman Begins was the best one released. Constantine (a loose Hellblazer adaptation starring Keanu Reeves) has now become a cult classic.

Marvel adaptations were much less successful. From Tim Story's middling-at-best Fantastic Four to the woeful Elektra. Original film Sky High was a moderate success, but The Adventures Of Sharkboy And Lavagirl wasn't particularly successful.

8 2011 Saw Six Superhero Movies Released And The MCU Get Going

2011 Superhero Movies

While the 2000s had plenty of superhero movies, the genre only started to dominate Hollywood in the 2010s with the rise of the Marvel Cinematic Universe. 2011 set the stage for The Avengers with Thor and Captain America: The First Avengers, both moderate successes. X-Men: First Class gave its series new life.

RELATED: Superhero Movies: The 10 Most Iconic Moments, Ranked

Less successful were Ghost Rider: Spirit Of Vengeance (savaged like its predecessor). Green Lantern (which forestalled DC's plans for a cinematic universe of their own). And lastly, the forgotten parody/Seth Rogen vehicle, The Green Hornet.

7 2014 Saw Three Successes, Three Disappointments

2014 Superhero Movies

Marvel Studios released two of their best films in 2014 - Captain America: The Winter Soldier and Guardians Of The Galaxy. Captain America remains the best film the Russo Brothers have directed. The latter, helmed by James Gunn, is one of the few Marvel films dripping with personality. X-Men: Days Of Future Past satisfyingly resolved both timelines in the franchise.

On the flip side, Robocop and Teenage Mutant Ninja Turtles were failures, and The Amazing Spider-Man 2 underperformed.

6 2018 Took Things Further With Seven Superhero Films

2018 Superhero Movies

2018 would be the year of Marvel, every year afterward was fighting for the title. Of the seven superhero films released that year, five were based on Marvel characters. 3 Marvel Studios films - Avengers: Infinity WarBlack Panther, and Ant-Man & The Wasp. One 20th Century Fox film - Deadpool 2 - and one by Sony - Venom. Warner Bros extended the DCEU with Aquaman, while The Darkest Minds was a failed attempt at a original superhero story.

5 2021 Had 8 Superhero Films

2021 Superhero Movies

2021 saw a wave of eight superhero films. Black Widow, Shang-Chi And The Legend Of The Ten Rings, and Venom: Let There Be Carnage had been held over from 2020 thanks to the COVID-19 pandemic. Marvel Studios also released Eternals and collaborated with Sony once more with Spider-Man: No Way Home. 

Warner Bros released The Suicide Squad and Zack Snyder's Justice League, a cut so different from the theatrical it can be considered a separate film. Hasbro & Paramount snuck in with their own attempt at a franchise builder, Snake Eyes, to a muted reception.

4 2008 Saw An Influx Of 9 Superhero Movies

2008 Superhero Movies

2008 was the year in the 2000s with the most superhero movies. Two of these films, The Dark Knight and Iron Man, changed the genre forever. The Dark Knight brought unseen prestige to superheroes. Iron Man gave Marvel Studios industry and audience credit. Hellboy II: The Golden Army wasn't as successful, but it ranks with high quality.

The Incredible HulkJumper, HancockSuperhero Movie, and The Spirit didn't fare as well. The Spirit, directed by Frank Miller, proved talent in comics doesn't translate to talent with film.

3 2016 Saw Marvel And DC Most Directly Compete

2016 Superhero Movies

In 2016, the MCU was well-established - Captain America: Civil War and Doctor Strange were both general successes. Warner Bros had a much rougher year - Batman V Superman and Suicide Squad were disappointments. 20th Century Fox had a mixed year; Deadpool was a success, but X-Men: Apocalypse underwhelmed.

RELATED: Marvel: 10 Events That Had The Longest-Lasting Effect On The Main Continuity

Unlike most DC Animated movies, Batman: The Killing Joke earned a brief theatrical run, which it definitely didn't deserve. TMNT 2 and Max Steel also made it to theaters, but wasn't viewed by many. With nine superhero films, 2016 was definitely a year for quantity over quality.

2 2017 Was One Of The Better Years For The Genre

2017 Superhero Movies

2017 had as many superhero films as the previous year, but was a step up in quality. Logan earned the highest praise a superhero film had since The Dark Knight. Logan has genuine emotional weight and a conclusive quality. Marvel Studios released Guardians Of The Galaxy Vol. 2 and Thor: Ragnarok, two of their strongest efforts.

Marvel and Sony produced the serviceably entertaining Spider-Man: Homecoming. The DCEU finally had a hit with Wonder Woman. M. Night Shyamalan continued his redemption with SplitPower Rangers was better than expected but underperformed, while Sleight was a genuine superhero indie movie.

1 2019 Saw The Apex Of Ten Superhero Films Released

2019 Superhero Movies

2019 was the height of quantity in superhero movie releases. Marvel Studios produced Captain Marvel then Avengers: Infinity War, while Spider-Man: Far From Home was another Marvel/Sony collaboration.

20th Century Fox's X-Men series went out on a whimper with Dark Phoenix. WB saw two different successes with Shazam and Joker. Most interestingly, the film industry saw wide releases of four original superhero films - GlassFast Color, El Chicano, and the Superman horror-parody Brightburn.

NEXT: Every Major Avengers' Age During Endgame